I like it, i think people are missing synergies with plate armor, loboing of your own vannillas with mindflayer, and in worst case scenario would RT leave a daughter creature behind as well as returning the seeded creature? if so i see a very good stalling tactic.
You missed the obvious synnergy with angels as well.
I actually like the cost right where it is now. Any cheaper and it becomes far too powerful if used on creatures like dragons.
Pop this onto a light dragon and hit it with heal several times a turn. Thats just nuts if it only costs 4 / 3 to put on.