can someone help me with the mefisto fight
the mefisto fight is a tricky and long one (i'd say it's the one i spend more time doing, due to the difficulty of it, the slow animations on his attacks does not help)
in order to be able to cause him some serious damage you need to first knock out the heart and the skull and THEN attack mefisto, do not attack mefisto from the get-go.
When the skull and heart are defeated Mefisto will change his moves to a more violent mode, but for a while your attacks will be effective against him (but you won't notice becuase he raises his defense to 100%), after a while he'll call out either the heart or the skull again, when he does focus the heart/skull until they are defeated and then resume to hit mefisto... it a bit of a boring and infuriating fight because the annoyance of having to defeat the sub-enemies again and again and not being able to do much to the main boss until you did so.
I'd recommend using the Catgirl (not kitsune), because Mefisto may be immune to being burned... but he is not immune to poison, and him getting a -10 of health each turn is helps quite a bit.
Also i recommend using fighters that can hit many times on one turn or debuff to counter his ridiculous defenses once he awakens, so if once he awakens you immediately debuf his defenses things should be easier.
I believe the team i used for that fight were The Catgirl (sweet sweet poison claws), the Cerberus (immune to fire, which is nice) and the Gargoyle (unable to be frightened).
also pack a shit ton of potion and all that you need... it's a long fight no matter what and an annoying one.