Bounty: You may tap a unit with 1 or more captivity counters on it in any arena.
When your build step starts, you may choose one: Put 1 captivity counter on one of your opponent's units in the Space arena. Or: One of your opponent's units with 1 or more captivity counters on it in the Space arena gets "Upkeep: Pay 1 Force or tap this unit." until end of turn.