I just beat my first mythical+, Scarlet, with gremory! Technically I beat Nordis with Minerva, but that was mostly due to dragonkiller Tsubaki and being basically immune to damage 80% of the stage, so it doesn't feel as real.
Real talk, what does everyone due for true damage for the predra floors? I actually am really liking Grem/ A.Yomi/ DD Akechi/ DD Cecil/ DD Pandora, but I am having to switch one out for a true damage sub, which sort of sucks. I'm guessing I should inherit something on someone, but I'm not sure who. Yomi is, at this point, the one with the least essential active, but I'm not sure what to go with. Inheritable true damage/poison I have amounts to A. Ra, Rodin, lumiel, I believe. Lumiel is interesting, as it makes a potentially akechi-able board, but it also could eat an OK board, so I'm not sure. Ra is the easiest, so probably the best option overall, but I'm not sure. Rodin still takes forever to cooldown (do I really have to pi him eight times?) and I'm unsure if killing something with poison breaks my shield for the next floor (would be bad for DQ hera following a predra floor).