hardest bosses you have defeated

[Sephiroth]

Aeronite and Ereshkigal in FFXIII: LR. They were very technically demanding and required a very precise strategy to succeed. Ereshkigal is probably the tougher of the two due to you having to attack it in the air, and air attacks in this game are tricky to maintain.

Ereshkigal is actually the weakest of the optional bosses. If you don't have a high enough damage output for Aeronite, it'll just fly away eventually. Then there's Bhunivelze + which is more difficult than both of those bosses. The only boss I haven't beaten in LR is Aeronite Chaos mode; sooooo much hp .

That's true, but I could never master the 'light slash to attack to light slash' combo you have to do for damage and elevation.

I forgot about Bhunivelze. Even his regular form is a bitch to take out, as least as far as final bosses are concerned. If you've done everything, most final bosses are actually pretty easy, like Braska's Final Aeon, Vegnagun, etc. But even after defeating the two superbosses of the game, I struggled to take down the big bad. He just has an array of attacks that are difficult to defend against, and with four forms, that's a lot of attacks to remember.

This is Lightning Returns. It has Overclock that can be used till doomsday and be combined with Artemis' Arrows, the most broken move to ever exist in a Final Fantasy.

And that means a lot because Crisis Core has Costly Punch, the easy 99999er.