Ah, true, guess there's that. lternatively if I manage to get SOME form of fire Atk multiplier lead, I could make a fire team to take him on and thus get to effectively use my Echidna(freshly evolved to final stage, too. Stupid Carmine Mask. Wound up getting it from Sword of Flames in the end). Unless anyone HERE has Orochi, though, I don't know anyone who owns/uses one.
I don't think you can burn him down in time without any sort of endgame capable monoteam, even with Echidna.
What you can do is evolve your Devil Dragon, that way he gets 50% dark resist so that + Odin = 90% Hades reduction, which brings it to a much more manageable 6666 HP from whatever puzzlemons you want every 6 turns to deal with (this is what I did to clear it). It's that (or Orochi) or use Chinese/Egyptian combo powpow leaders. If you can give me a time window you want him up, I can put my Babby's First Odin up - I learned with Yukarin with the rank differences otherwise my guy isn't going to show up :V
IN OTHER NEWS
So I bring my ragtag team of

mons, roflstomped through the first 3 stages, the fox lady wasn't so bad and then
:ohdear: :ohdear: :ohdear: :ohdear:

:ohdear: :ohdear: :ohdear: :ohdear:
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:3