The game has a total of 122 collectibles (80 Lost Souls, 21 Doors and 21 keys). Take note that you can't collect them all in one playthrough since you'll need certain weapons and abilities to reach them. You can freely replay the previously completed missions but I suggest going through the story missions without worrying about the collectibles that much then just replay the missions to collect all missed collectables.
The collectibles you find and collect are automatically saved so you don't need to wait for the next checkpoint to leave the mission. It is also suggested to acquire the ability "Leap" as it will be handy in further reaching hard-to-reach areas.
Lost Souls are those agonizing, trapped spirits, often found on walls. You'll know if there's a soul nearby by hearing a painful and slow moan in the area you're in. Look on the walls above and behind corners as they are usually located there.
Mission 1: Souls 6
Mission 2: Souls 9
Mission 3: Souls 3
Mission 4: Souls 8
Mission 5: Souls 6
Mission 6: Souls 2
Mission 7: Souls 8
Mission 8: Souls 5
Mission 9: Souls 2
Mission 11: Souls 7
Mission 13: Souls 7
Mission 16: Souls 9
Mission 17: Souls 5
Mission 18: Souls 3
Lost Souls: 6
1: You’ll find this soul immediately along the way.
2: Inside the doll/horror house and after the hunter bursts through the mirror at the end of the pathway, continue forth to the next corridor and turn around to find another Lost Soul on the wall.
3: In the same corridor after getting #2, before heading downstairs, approach the large doll on an electric chair and enter the room beside it. Turn around again and look above the doorway to find another Lost Soul.
4: [Requires: Eryx] After meeting Kat, turn around to find some red crystals. Destroy them to find the soul inside.
5: [Requires: Angel Lift] After reaching the merry-go-round with the divinity statue nearby, go to the alley behind them to find some angel lift targets. Swing using them to reach the lost soul.
6. [Requires: Arbiter] After the scene where the hunter bursts through the mirror, check the hallway to the right to find a damaged door. Destroy it to find the last lost soul in this mission, including some red orb sources.
Lost Souls: 9
1 and 2: After leaving the room with Sparda’s painting, the wall in the next hallway will retract so to reach that soul, you have to double jump and air dash to reach it. (Or wait until you get Angel Boost later on) Jump to the hole below and find another lost soul on the wall to the left after landing.
3. After getting souls 1 and 2, follow the path until you reach the main hall before. Kill the enemies then go upstairs to find a red, slashed door. Smash it using the Arbiter. Before moving on, turn around and look up the doorway to find another lost soul.
4. Past the copper door, continue to the next hallway then pull the platform for you to cross. Before crossing, turn around and look above the doorway to find another lost soul.
5. After obtaining the Osiris, head back to the hallway and destroy the white barrier to reach a room with a Lost Soul above the doorway.
6. After getting #5, head outside and jump on the platforms to reach the next door. Slice through the blue webs then before moving forth; turn to the corridor to the right to find another room with a Lost Soul and a Copper Door. Reaching this room can take a few attempts since you need to perform a long double-jump with a timed air dash. (If you're having difficulties reaching it, wait until you get the Angel Boost ability)
7. [Requires: Aquila or Angel Boost] After reaching the divinity statue, turn to the right to find the angel webbing across the broken floor.
8. [Requires: Angel Lift] After leaving the large room with Sparda's painting, jump on the broken floor (past where you can get the Argent Key) then jump down to another broken hallway. There's an angel lift target to the left which leads to a room with the lost soul.
9. [Requires: Osiris or Aquila] After smashing the red, damaged door open while following the ghastly kids playing, you'll find a room with an angelic web blocking the entrance. Destroy the web to find a lost soul inside.
Lost Souls: 3
1: Try to regroup with Kat only to discover that your path is broken. You have to find another way so turn around and free the lost soul overhead.
2: After returning to the plaza and obtaining the Angel Boost ability, jump from the top of the central statue in the plaza to reach this soul.
3. After getting #2, you can double-jump then angel boost to reach the angelic web on the upper wall nearby. Destroy it to find another lost soul inside.
Lost Souls: 8
1 and 2. Take all the enemies in the starting area then free the lost soul in the dark corner to the right. Turn to the left then pull the platform using Demon Pull then reach it by Angel Lift. Jump to the next ledge and free the lost soul in the corner.
3. After destroying the first camera and as the street ahead gets torn, don’t go downstairs yet. Go upstairs to the left to find a vitality star. There's another lost soul just in front of it as well.
4. Found in a plaza with a small fountain fixture in the middle and divinity statue nearby. There's a nearby lost soul by the window near the fountain. You may need to stand on top of the fountain fixture then angel boost to reach it.
5. In a plaza with a small fountain fixture in the middle. There's an angel lift target at the edge of the building beside the broken street but you need to stand on top of the fountain fixture again then angel boost to get in range. Pull yourself up and destroy the soul on the window.
6. Pull yourself up the platform near the divinity statue. You should see a lost soul on a high window not too far ahead leading to the dead-end.
7. Enter the alley past the building where the Argent Door is located. After the scene, use demon pull to change the stairs into a platform. Climb on it then use demon pull again to create more platforms that will enable you to reach the next building. After reaching the building, turn around and you should find another Lost Soul on the window across.
8. Get back to the roof of the building and destroy the door with Arbiter to find the last lost soul inside.
Lost Souls: 6
1. After entering Limbo from the warehouse, continue hopping on the floating platforms. There's a lost soul here but it can be difficult to give directions so kindly refer to the video below to reach it.
2. In the platform of the first area where you fought the hell knight and tyrant (same area as the copper key), don't leave yet. Look at the edge of the platform then jump and immediately pull yourself using angel lift to reach the other platform containing a lost soul.
3. Upon reaching the vast warehouse with more floating container vans, pull yourself to the next walkway then look to the right to find a lost soul.
4: In the same area, there’s a lost soul on the upper ledge before the entry to the mixing room.
5. To the far right wall of the mixing room entrance, there’s another lost soul to be found.
6. [Requires: Aquila] Head to the large warehouse where there's a lot of floating cargo. There's one container van there with an angelic webbing. Destroy it using Aquila's charge attack then use angel lift to reach the upper platforms and the last lost soul in the area. Refer to the video below for more details.
Aquila Lost Soul, Virility
Lost Souls: 2
1. In the first area, keep running and quickly destroy/ avoid enemies before the time runs out. After pulling a platform and crossing a long chasm, turn around and you should see the first of the two souls in this area.
Lost Soul 1, Secret Ingredient
2. After reaching the second area, turn to the left to find another lost soul.
Lost Souls: 8
1. Continue along the path until you reach some red crystals. Ignore them for now and turn to the left to find a lost soul. Free it then destroy the obstacle.
2. After reaching a large area with container vans nearby, Go down the ramp a bit, then jump to the ledge on the left. Rotate your camera to the right and you'll find another ledge to the side which leads to an enclosed floor with a Lost Soul and a golden door. (Secret Mission: Divergent Slaughter)
3. After taking out the Rage enemies, jump through the hole on the wall then turn around to find another lost soul overhead
4. After reaching the elevator area, check the pathway to the right to find this soul.
5. In the elevator area, continue up to the top floor. Before leaving the ramp, turn around and jump across the ledges to find more red orb sacs and another lost soul at the end.
6. After brining the elevator down, head to the next room but stomp on it yet. There should be another lost soul in the corner.
7. After reaching another divinity statue, turn around to find more red orb sacs and another lost soul.
8. [Requires: Aquila] After getting the copper key, swing to the other side to find the last lost soul in the area.
Copper Key and Lost Soul, Overturn
Lost Souls: 5
1. After reaching the train tracks, check the end of the tracks to the left to find this soul on the wall.
2. After reaching the divinity statue, check the alcove to the right to find a soul
3. After reaching the harpy nest, enter the Platform 1 tunnel.
4. After reaching the harpy nest, enter the Platform 2 tunnel.
5. [Requires: Aquila] In the start of the mission while following the harpies, you'll be in a tunnel that will stretch out. Before destroying the red crystals, you should see an angelic web across. Destroy it then go there. You'll find the lost soul on the wall ahead.
Lost Souls: 2
1. Just continue along the straightforward path from the starting point of the mission and you’ll come across this soul behind some angelic layer.
2. After using Assiel's statue to reach the next building, you'll immediately find a lost soul behind the windows upon landing. Turn around and jump to the ledge outside to reach the soul.
Second Lost Soul, Devil Inside
Lost Souls: 7
1. Inside the apartment building, you’ll find an angelic layer across the gap. Destroying them allows you to collect the vitality star and red orb sacs. Once you drop down to that hole and turn around, you’ll find the soul.
Apartment Lost Soul, The Order
2. Once inside the Order’s HQ and shortly after defeating a butcher, tyrant and witches outside, continue until you reach a large hall with angelic vines overhead. Turn around and look to the upper left to find another lost soul.
3. After the HQ’s door is blasted open, go downstairs then turn to the right towards the red light. Turn right again and look up behind to find this lost soul.
4. After getting #3, backtrack and enter the corridor with green light. Check the corridor to the right to find another soul.
Headquarters Lost Soul, The Order
5. Backtrack to your starting position in this floor, then check the other corridor until you run across a slashed wall and red crystals at the end. Smash the wall to find a soul inside.
Headquarters Lost Soul 2, The Order
6. Outside the hallway where #5 is located, smash the red crystals and go around the corner. Look up the archway to find another lost soul.
Headquarters Lost Soul 3, The Order
7. This is found near the ceiling of the round room where you’ll fight the dangerous Drekavac. Unfortunately, you have to use that fast and dangerous enemy as a stepping stone to reach it. Another problem is that this enemy can't be easily pulled; you need to catch him off guard like the instant that you evade his attack. It may be a bit tricky but you can pull it off with practice. Refer to the video below for more information.
Headquarters Lost Soul 4, The Order
Lost Souls: 7
1. After surviving the few fight rounds with Lilith’s minions, she’ll alter the whole area. Turn around afterward and double-jump on the raised floor behind to find this lost soul.
2. Go past the divinity statue but don't go up the ramp. Check underneath it to find a lost soul.
3. You’ll eventually have to tread two walkways comprised of red demon and blue angelic tiles. Make your way to the floating platform to the right. Here you'll find some green critters and a lost soul.
Angelic/Demonic Floors Lost Soul, Devil's Dalliance
4. After clearing round 3, stomp on the pressure plate and you'll find yourself in a dark blue room. Turn around and you'll see a lost soul on the wall.
5. After clearing the room of annoying rage spawns, continue upstairs and ignore the pathways that will be created but instead, use angel boost to get in range of an angel lift target on the floating platform to the right. Continue to the next platform and stomp on the pressure plate to create a walkway to the next platform. You should find another lost soul on the wall.
Blue Floor Lost Soul, Devil's Dalliance
6. After completing the secret mission/ finding the door, don't proceed yet. Look around to find an angel lift target on a floating platform in front of the divinity statue. Get yourself there then look up behind you to find another angel lift target. Go up there and to the next platform containing a devil trigger star and a lost soul.
Secret Devil Trigger Lost Soul, Devil's Dalliance
7. After getting soul #6, get back to the main path and continue until you reach another platform where the last lost soul is located. Stomp on the pressure plate to continue as well.
Lost Souls: 9
1. From the divinity statue, take the stairs to the left to find the elevator and a slashed door. Smash it open and follow the stairs to reach a lost soul and a vitality star.
2-3. After reaching floor 105, go to the right (the side where the “1” is) and go around to find a key and two lost souls past an open shaft. The floating blocks will damage you so you have to wait for them to disappear then jump across to reach them.
Three collectibles, One Shaft, The Plan
4. Once you found the floor 106 sign, go around and find the shaft in the middle. Boost to the middle and enter the door to the left to find a stairwell. Go up and you'll find a lost soul. Go downstairs and you'll find a Gold door.
Two collectibles, One Stairwell, The Plan
5. Backtrack to floor 106 and you'll have to swing using the angel lift targets. Instead of swinging across, deliberately fall down to the lower floor and clear the enemies there. You'll find a devil trigger star on the table and a lost soul inside the door with an angel web.
6-7. Backtrack to floor 106 and you'll have to swing using the angel lift targets. Instead of swinging across, deliberately fall down to the lower floor and check the elevators to find two lost souls there.
8. Upon entering the next door past the corridor with alternating lasers, turn to the left to find a lost soul on the wall.
9. After meeting Vergil in the elevator and getting the Kablooey, continue along the path until you reach the next sky bridge. Don’t go there yet; instead, keeping heading straight to find this soul.
Furnace of Souls
Lost Souls: 5
1. As soon as the mission starts, jump on the platform and take the path to the left. Make sure to take your time and above the deadly soul stream erupting from below. After swinging to the platform with a wall, check the back to find a lost soul.
2. (You can restart the level to avoid having a death penalty to your evaluation at the end of the mission). From the starting position, take the right path this time and defeat the hell and frost knights. Look to the left to find a demon pull target across. Boost there and pull the wall to remove it then quickly use angel lift to reach that platform. You'll find another soul there.
3. Make your way to the main platform where you'll have to fight two waves of enemies. After clearing them, check the corner near a green health sac to find a lost soul.
4. Continue until you reach the platform with a divinity statue on it. Swing to the other platform and defeat the enemies. Look up on the wall to find another lost soul.
5. In the last platform, free the soul behind the large rock to the right.
Lost Souls: 3
1. Next, go to the southeastern path first. Follow the path until you reach the generator. Before kickstarting it, look up to the left to find a lost soul.
2. From the main area, take the southwest path this time. Continue to the end of the path. Before jumping below, stop at the edge and look to the right to find another lost soul. Double-jump before angel boosting to reach it.
3. Finally, make your way to the last generator through the northwestern path. Here, the last door and lost soul will be right in plain view so it's impossible to miss them.
Argent Door and Final Lost Soul, Demon's Den