Have someone mentions Fractal?
For a 3 damage (average) and practically unkillable critter, this would feel OP.
Compare Frogtal which can be trumped with a single RoF.
Fractal makes everything OP...
Example : Fractal a scarab and each of them costs only 2 quanta. But the scarabs will become large enough to devour every single creature in the field
By the same argument, Eternal Phoenix is OP.
But no, really. While Scarabs can still be killed with enough RoF, lobo'd, denied, this card can't. Get them out, got weaker average damage than Minor Phoenix, immortality forever.
Phoenix: 4 dmg, immortality, need
, delay a turn
Ouroboros: 3 average damage, immortality, no upkeep, no delay