the only boss I've ever faced in that list is xemnas in KH.
but I'd say final fantasy 3 and its 5 bosses at the end without being able to save in between is really really gay.
that's why i quit it a 2nd time. lol
yea i was called a noob for trying to get 2 tgs for my phreeoni and they said phree is 40 coupons. later that person buys it for 45 coupons and gets killed by me in pvp. q.q