Experimental Emphasis

{6}{t}: Remove target creature from play and put
it under Experimental Emphasis. During any of
its owner's turns that player may pay {3} to return
the creature to play under its owner's control and
roll a d6: if the result is odd put that many -1/-1 counters on the creature, if the result is even put
that many +1/+1 counters on it.
Only one creature may be under Experimental Emphasis at a time.