Lifeform Hojo
In his final form Hojo can attack insanely quickly and is not effected by slow, so you will just have to deal with his damage output. His attacks can also cause negative status effects and cause near 500 damage. His combo attack combines several of these attacks together so you can see the need to keep your health way up during this battle.
The Counter Attack materia is a good one to use here as each of the combo hits can be countered, so make sure you have them on your character. If you want to beat Lifeform Hojo in a cheap fasion you could equip Barret with three Coutner Attack materia and his Missing Score weapon found earlier in this area.
Hojo can cause many status effects and has a habit of using skills that hit your entire party so keep esuna and heal ready, remedies could also be used, as well as casting haste, big guard, wall, and regen on your party. Stay away fro gravity attacks as they will have no effect on this boss.
For surviving this trifecta of deadlyness you get a single Power Source.