I like this card a lot. It hits my nostalgia for Morphling right on the nose, while feeling like much more of a modern card.
That said, I think it's pretty low-power for a six drop blue creature relative to cube (or seven-drop, if you want to hold up flicker mana). Once it's resolved, it doesn't do a lot to stabilize you... it's tough to kill, but it only stops one non-evasive creature. Ultimately it's just good at attacking for 8 unblockable damage, which is fine, but does cost five mana every turn.
For my part I'd rather include Deadeye Navigator in a low-absolute-power, high-synergy, high-sweetness slot around this mana cost.