Metal Gear Rex man now I want MGS1 all over again haven't played it like forever
Yunalesca she was hard even if you know what you are doing
Sin not hard just get three Magus sisters and use them he's BBQ then
KH Phantom only because four things
1. Had to use Magic 90% of the time
2. Make sure your characters didn't die then it would have been harder
3. Make sure you stop the clock
4. Make sure Phantom himself didn't kill you because he takes a chunk of your HP if you do get hit
KH2 Sephy maybe there is a pattern but you cannot attack this guy head on he will cut you down I still haven't beat him
Sephy is not the hardest boss of all time maybe for RPG's that's about it