The first one (two ) was easy enough with Nul magic, Anima was a joke against Shiva, and you consider it has MUCH more health than the Anima you can get yourself which implies it is of a much higher level, it's pain causes 600 to 800 damage and Oblivion only caused 100 to 200 per hit which was a joke.

The 3rd was hardest but after levelling up a bit was pretty easy.

The 4th was a joke considering by that point I'd done the Omega Ruins, I won in two turns, two of my turns that is, damn turn-stealing cheater