I think I'm going to try it out, but I likely won't spend stones. My team is:
Duke (lvl 59/max skill)
CDK (lvl 64/max skill)
Awoken Hera (lvl 59)
Hera (max)
Demon Viper Orochi (lvl46)
OR
Echinda tRE (lvl 55)
Zeus friend
I know I need to pump some levels in but I'd like to get a feel for the dungeon and maybe really go for it next time.
From what I understand, there's no way you can clear this without using stones because you'll die on every hit or so from Zeus.
That said, you're probably better off using Orochi than Echidna simply because he delays for longer, giving you more turns hacking away at him.