Dakkodango Translations

I got a couple of questions about the final mission the maze where you fight the eternals

1. is there a way to train my characters or leave the maze, if not, then why am i finding Mana Crystals

2. How to i even fight the Eternal on the right (can't remember her name but she's sadistic and one of her attacks has her remove her coat showing she's wearing very little), i fought her as Tokimi (Level 35....i think, she hasn't leveled up since i got her) and with one of my strongest defense squads (roughly Level 28, apart from Farren, Hilion and Yuuto i've leveled everyone equally to at least 28) and i can't even attack and Tokimi keeps dying on the 8th and final attack

i apologies if these questions have already been asked, tried the search but all i got was posts asking if you would to become an Eternal

1. You can release those mana crystals for 30 mind spread between everyone in the group (i.e full group of 3 = 10 mind each, eternals = 30 mind.)

2. You'll need someone with a lot of attacks to hit her, black spirits, Tokimi's Accelerate Time and Yuuto's Aura Photon Blade are good choices.