Experiment Reborn

Eternal (You may cast this card for {4}{u}{g} if you
put a counter on a permanent this turn)
If five mana or less was spent to cast this card, it
enters the battlefield with your choice of a
first strike, hexproof, flying, or menace counter.
If six or more mana was spent to cast this spell, it enters the battlefield with four +1/+1 counters.