comment on the diablo boss strategy part:

instead of drawing and casting demi from diablos right away, i think u should draw it and stock it, then on the next turn use the demi on him. for some reason, after u do that, he casts curaga on the caster. at least i'm pretty sure that was the case. maybe if u somehow have ur own demi's those will have the same effect but i did that a lot and i didn't even need to use limit breaks. after using demi enough times, i just boosted up my shiva and quezacotl and it was easy enough.just something u might wanna try ^^