At the beginning of your upkeep, put a
shield (If the creature would be dealt damage or destroyed, remove a shield counter from it instead.) counter on target creature an opponent controls.
Whenever you put one or more counters on a creature you don't control, tap that creature and
goad (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.) it. It gains
trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.) until your next turn.