but there are special bosses after you defeat hollow bastion in the old worlds like agrabah
Yeah at Agrabah there's Kurt Zisa.
And at Neverland there's the Phantom.
k i am stuck on rock titan
I don't know if i just was lucky, but i have no clue how that guy got to first seed. Stay close to his feet, but not too close, or you'll get stomped on. Pull lots of combos on him, but not special combos like Ragnorak and Ars Arcanum, that'll pull you under his feet and you'll get crushed like a bug. When he falls on his knees, then use the special combos. Attack quickly becuz eventually (i think) he has a harder mode. I never saw it.