Nautilus on 05 June 2016
For me it would be Hard Balls from Pursuit Force and Jecht Final Summoning(FFX final boss).Both of them took me weeks to finally find a way to beat them.They were trully wore my mind and body down.
Edit: Oh and Misterious Figure from Kingdom Hearts Birth By Sleep.That guy was freaking OP wioth his 1 hit kill.Again took me weeks to finally beat him, and I only manage to kill him once.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1
