Shin Megami Tensei: Digital Devil Saga

When you get Satan down to half health (15,000) he will start to use a skill called Temptation, which charms all members of your party ,and is 100% accurate. As soon as you get him under 15,000, cast void charm/ailment as the next turn will be Temptation. After this, he'll use it the turn after he uses Dekaja. This is also why you need to keep a check on how much HP Satan has remaining, otherwise it can royally screw your battle up.

This also leaves you vulnerable to Mamudoon, so you just need to hope that he either doesn't use it or it misses if he does. He'll also start using stronger spells now, so keeping your health up is vital.

Is that everything? Hell no, the worst is yet to come!