Challenge lv 7 FINALLY cleared (I dont want to think about all the stamina it took...)
Team was Isis, Echidna, Kushi, DKali, Nut, Isis
Despite having poor HP, I eventually realized I really had to use Echidna to handle all of the low HP bursts. Kushi is there for added anti-burst support and to help stall which was crucial. DKali helped handle all of the jammers and poison orbs. Nut was there for stats and blue orb support.
Floor 1 is pretty much super easy for me now after all those tried although I did die to it a few times. Basically evenly chipped away at both and then finished off with Nut active.
Floor 2 is the second hardest floor. Stalling on them isn't to hard but trying to balance brining them to low HP without getting too low but and also not killing one by accident is difficult and easy messed up by skyfalls. Echidna is useful even though she doesn't affect Thoth since you can bring them both low, delay Sopdet, kill Thoth, and then kill Sopdet after without having to worry about the revive. I actually screwed up after used Echidna resulting in Sopdet getting revived, but I then killed Thoth so they both got revived to 50% and then went back to stalling.
Floor 3 is best floor not too bad. Brought her to just above 50% then delay and finish. Even if I accidentally get skill bound, I have enough HP to tank one strong hit. It does make the next fight even harder though.
Floor 4 is ugh. Basically just have to pray that rng doesn't screw you over with a ridiculous attack pattern, like switch you with Echidna, then heart kill, 99% gravity, and 15k hit. All actives were used liberally.
Floor 5 isn't too bad but it's potentially devastating if you screw up. Unlike most bosses, he's one of the least RNG based bosses in the game because he always converts the exact same orbs. The tricky part is after he gives you heart orbs, you need to heal up but also save some for the next hit, and also make sure not to have heart orbs in the middle row or else they get welcomed to the space jam. After stalling for everything to be up, hit him low with a Kushi shield protecting me from his low HP burst, then Echidna'd him and then that was pretty much victory \o/