Mission 10: Titan's Realm

Use the artefact up ahead for more storyline information and drop down the throat of the huge skull up ahead. Three Cacodemons show up, so defeat them with rockets or plasma. Grab the loot in this area, go upstairs and waste the Mancubus with rockets. In the next area, try killing a Lost Soul by destroying another. After clearing the area, hop underneath the bridge (carefully, so you don't land on the poison) and hit the skull switch. Go back up and check out the opening to the far lower right that leads to an Elite Guard.

Mission 10 - Elite Guard #1

Back up, continue through the halls and grab the armor, spawning two Hell Knights. Waste them and step back to trigger a few hidden walls, revealing Unwilling. Defeat them and hit the skull switch that appeared, spawning a Mancubus in the distance around the corner. Kill it with rockets, then turn left before proceeding. You can find a Field Drone in the newly opened room.

The next room, where the Mancubus came out of, contains a lot of demons. You're up against a Revenant, a Mancubus and Cyber-Mancubus, quite a few Imps and also a Hell Knight and two Pinkies. Use rockets on the Mancubi and the Super Shotgun on the rest. Grab all loot (don't lose your mind over the Mega Health behind the bars - you can only get it later on), defeat a few Unwilling coming out of a wall and then, after clearing the area, step inside the portal.

Another huge battle ensues. You're up againt two Revenants, at least two Hell Knights, a lot of Imps, various Mancubi, and last but not least, at the end, two Barons of Hell. Save your Chainsaw for one of those behemoths. To get that far in the first place, use the rocket launcher on the Mancubi and the Super Shotgun on everything else while staying on the move. There's a Quad Damage Powerup on the lower left side of the area. Use it in combination with the Plasma Rifle to defeat the Mancubi and Barons of Hell easily near the end.

Defeating all demons in this area unlocks a hidden room on the upper level. Climb upstairs and move to the corner to find the hidden chamber with the Keenguy Collectible.

Mission 10 - Keenguy Collectible

Go through the portal to reach a new area with various Unwilling, Lost Souls and a few Hell Razors. Shoot the explosive 'barrels' to quickly eliminate the Unwilling and Razors and use the assault rifle on Lost Souls. When the coast is clear, use the yellow launch pad to reach the upper platforms. Move from platform to platform to the far corner to reach the Silverguy Collectible.

Mission 10 - Silverguy Collectible

To continue, jump to the armor on the upper level and go through the smal passageway up ahead. Interact with the skull and the ceiling will come down. Look up and move back to the gate where you came from; you should be able to squeeze against it so you don't get crushed. Afterwards, drop down to the poisonous area. Unfortunately, the yellow door is blocked by a gate. Turn left past the green lanterns and make your way to the end of this poisonous area (note - but don't grab - the Invulnerability Powerup in the middle/side of the area). You'll find an Elite Guard at the end, along with a Skull Switch.

Mission 10 - Elite Guard #2

Use the Skull and quickly move back to the Invulnerability Powerup. Go to the Mancubi up ahead and empty your rocket launcher on them, then quickly continue to the next area and defeat various Pinkies here with the Super Shotgun. When the coast is clear, wait with going through the yellow door and check out the other opened-up room first to find a Data Log and an Argent Cell. Note that selecting ammunition will also grant you three BFG rounds, so if you're low on those it's an excellent choice.

Mission 10 - Argent Cell

Move through the yellow door and you'll drop down, right into the next battle. Use your rocket launcher on the Mancubus and start slaughtering Revenants with your Super Shotgun. When more Mancubi show up, waste them with rockets.

When the area has been cleared of demons, jump from higher ground to the falling platform/lift to reach a switch. Hit it, go back down, move over the bridge, turn left and search the corner near the gate for a Classic Map Lever. Head back to the poisonous area, go down the steps and turn right to find it. Inside you can collect a Mega Health at the end by inspecting the wall with a deviant grey color. Not bad! Especially since it means infinite ammo with the Rich Get Richer rune.

Mission 10 - Classic Map

Head back to the area you just cleared. Continue through the hall behind the falling elevator and grab the ammo here. The portal has been closed for now, so continue through the next room and grab the Blue Skull at the end. When you head back, Spectres spawn (semi-invisible Pinkies). Waste them with the Plasma Rifle (as long as you have infinite ammo, who cares) or the Super Shotgun. A big fight against other huge demons ensues, among which many Mancubi, so pull out your rocket launcher. As a finisher a Baron of Hell spawns. You can use the BFG if you wish, since there's an ammo cell for it in the previous area anyway.

After clearing the room, head through the portal and move through the tunnel. Turn to the left and walk to the end to collect the Mega Health, which counts as secret. Interact with the Skull and go to the next area, which is in fact a familiar room. If you have the Rich Get Richer rune equipped, wipe out the lesser demons with your Plasma Rifle, including the two Mancubi that spawn. When the Summoners appear, grab the Berserk Powerup and waste them ASAP, along with the Hell Knights and the Baron of Hell that also spawn. Having cleared the area, go through the blue door and grab the Data Log behind it.