Well, his situation with kamihime's doesn't look too hot. How about running fire/dark team? Apocalypse will come back soon and she will support those elements.

Balor/Tsukuyomi/Amon/Nergal/Baphomet/Astaroth or Mephisto? If you go with Cassiopeia/Andromeda team like this could work for some time till you get SSR to support one of elements.

Or water team with Nike/Triton/Kushinada/Circe/Rusalka/Undine with Mordred as main soul and using R water eidolon that will give you 30% atk increase or daily water disaster till you can get your hands on something better (like garuda that eventually will come back)

As for what to get from ixion event, at least one of each (eido and weapon) after that I would say go for max eidolon, since you can get good weapons from disaster raids.

Or if you don't feel like sticking with your account then you can always reroll... I am not fan of rerolling but that is always an option.