Creature - Human Wizard Mutant 0/0, 2UU (4) Graft 2 (This creature comes into play with two +1/+1 counters on it. Whenever another creature comes into play, you may move a +1/+1 counter from this creature onto it.) {U}, {T}: Gain control of target creature with a +1/+1 counter on it as long as Cytoplast Manipulator remains in play.1
Illus. Dan Scott
It only tests that the target is a creature and has a +1/+1 counter when the ability is announced and resolved. After that, control remains even if it stops being a creature or having a counter. [Dissension FAQ 2006/04/13]
If this card leaves play before the ability resolves, then the ability does nothing. [Dissension FAQ 2006/04/13]