What are you doing now?

[Shin Gouken]

I don´t have three sentinels and my Snow is underleveled.

Your team get higher defense boosts with more sentinels. Having three is i think mandatory in this battle. When you get closer to the end of the battle, he starts hitting twice as hard so you're probabley better levelling your chars a bit

As for what i'm doing... i'm trying to get the treasure hunter trophy, i've done all the accesories and 3 characters have a tier 3 weapon. I thought i'd sell off everything i own to make Gil but it only came to somewhere over a million. This game is just way too stingy with the money