Shin Megami Tensei V: Vengeance SATAN (on Hard)

TIMESTAMPS
Fight begins: 0:33
Fight ends: 31:02
Relevant party check: 32:04
Featuring Ose from the Shin Megami Tensei series.
Tips: Strategically leave certain demons for Satan to plunder whose Magatsuhi skills won't ruin your run (i.e Twilight Wave or Shield of God), their race determines the Magatsuhi skill used, so pay attention. Try leaving them at the lowest HP you possibly can so Satan doesn't heal much off his plunders.
Your choice of Magatsuhi skills also matter, as you have to deal more damage than Satan heals off his plunders; try going for offensive ones like Succession or Doubler. Savage can work if you're close to finishing him off, but otherwise becomes a drain on your MP resources.
Megido Ark spam can be avoided without Mirage... if your party isn't fully buffed, and Satan's summons aren't fully debuffed, and your team isn't all immune to fire, but that's a lot to ask when you have to manage both Satan and his summons. Otherwise this is just a battle of attrition, manage your MP and damage well and you should prevail.

[@areasito]

Damn reim