Taokaka has some amazingly gimmicky ways to combo into her astral heat. It can combo off of backthrow, airthrow, bowling ball, taunt, and 6c. I'm sure there are others too.
Because of Taokaka's high damage it is possible to do 4k damage, mid-combo air grab, and astral heat
(CH 5B/5C) 6C 236CC 2d~6 j.C 9D~6 j.C 9D~6 j.C 9D~6 236BB airthrow astral heat
will kill most characters from 80% hp. Only problem is getting 100% heat and landing the throw