Final Fantasy: 15 Most Brutally Difficult Boss Battles

A superboss so powerful, it even gets his own location selectable by airship for you to actually fight the thing.

Penance may actually be quite a mystery, depending on where you're from, and/or if you've played the HD remaster of Final Fantasy X. In the original game, this superboss was exclusive to the PAL and International versions of the game.

Penance only appears after you manage to beat all of the Dark Aeons; twisted versions of your own summons from the game. These, in themselves, are extremely difficult to beat.

Once they're dispatched, you'll see a new scene showing Penance appearing over the Calm Lands, and you can travel to fight him on your airship.

Strap yourself in for this one. Penance has 12,000,000 HP, as well as two independent arms with 500,000 HP each. The arms attack you as well as the main body with powerful abilities, and the appendages will regenerate if you manage to kill them.

You're going to need all of your characters to have their fully-upgraded Celestial weapons for this fight to get through Penance's defences, as well as pretty much maxed-out stats on the sphere grid.

Even with that, Penance has an ultimate ability called Judgement Day, which inflicts 99,999 HP damage, and drains 999 MP. That's insta death for all, and can only be negated by using auto life.

You'll get a few items such as a Ribbon accessory for beating Penance, but given you've probably already beaten everything else in the game to get to this point, you'll likely not need them.

Hey, at least you beat it!