Avalanche: I like it, actually, though I fear its abuse in spam decks. This will go great against the more powerful shields that we're getting, though (cough cough, Hope).
Mind Control: Rather overpowered. As Scyther mentioned, take control of an Oty. Also, any mutated creatures, like the ones with Steal or Destroy, could be exploited to your advantage. Freezing your opponent's own creatures, poisoning them, and unburrowing them are some of the powerful ways you can exploit this card. Make it cost more, plox.
Revive + Summon: Maybe they're good ideas, but Elements does not have a "Graveyard" or "Discard Pile" or anywhere that dead cards go like other card games do. Thus, this cannot work.
All in all, some good, intriguing cards.