How do I clear chapter 7?

Equip 3 Scrolls from the list to everyone:

Book of Attacks Lv. 2
Book of Attacks Lv. 3
Null Numbing Lv. 1
Null Paralysis Lv. 2
Null Lethal Poison Lv. 2
Null Seal Lv. 2
Null Sluggish Lv. 2

Try raising your Attack power to around 300 or more,
Then when the Battle starts, use the Lightning Sword combo(Circle, Circle, Triangle) or the Chidori Stream(Circle, Circle, Circle, Triangle) as well as the Sharingan Combo(Circle, Circle, Circle,Circle, Triangle) The enemies should go down quite quickly.

If they don't go down Quickly, Try stunning them, and using the Kizuna Combo to finish them, but try getting a 30 Hit Combo or more for the most damage.

As for the Boss at the end, Attack him from Behind to deal the most Damage.

If you can't hit him from behind, then Attack him from a distance with the Lightning Sword Combo(Circle, Circle, Triangle) As well as the Fire Ball Jutsu(Triangle Button)

Also if you have the Regeneration Tag,(Can be found on the A-Rank Mission, Protected Princess) equip it to Karin so your health will restore itself continuously.

When at the menu before you enter the mission where you see the character's faces at the top of the screen, press TRIANGLE. You can then add scrolls to Sasuke and his team.

Use ninja tools(Sasuke has "Shuriken" and "Paper Bomb"). For some reason, they cause more damage than jutsu or combo finishes.

If you sasuke and others to be strong.....just press x and you'll see the game story of chapter 7 will release and press the triangle button for the character setup.....and equip sasuke the most strong scrolls

Equip the best scrolls to increase your attack for Sasuke. Equip the regeneration tag for Karin. Also, use shuriken as they cause a lot of damage. For the boss, use paper bombs, ninja tools and long-range combos.