Creature — Human Monk 1/1, 2G (3)
Uncommon
At the beginning of your upkeep, put a +1/+1 counter on Descendant of Masumaro for each card in your hand, then remove a +1/+1 counter from Descendant of Masumaro for each card in target opponent's hand.
Illus. Rob Alexander

6/1/2005: Descendant of Masumaro's printed power and toughness is 1/1, so removing all the +1/+1 counters usually doesn't reduce the creature's toughness to 0.
6/1/2005: The counters are added and then removed without a pause for priority or state-based actions being checked in between.
6/1/2005: All +1/+1 counters on Descendant of Masumaro are removed, including those put on it by other effects.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern