Hmm.. if you want to be nasty, add some tutors and
Arcane Adaptation.
With your commander, Joda/Fist and
Arcane Adaptation, you would be able to play every creature for 0.
Besides that, what about a focus on another tribal? the changelings would still work and it would be easier to take a look for lords or other cards that supports this specific tribal. With the stuff you've got until now, dragons seem to be a idea. but, at least technical, every other tribe would also work.
Another interesting option would be one of the
Sea monster tribals, because of cards like
Quest for Ula's Temple or
Whelming Wave. This would also allow some nasty tricks with Arcane Adaption, even if you haven't got jodah/fist out.