Yellow Diamond

+1: Detain target creature you don't control with mana value less than 6.
-3: Deal 3 damage to target creature or planeswalker you don't control. Tap that permanent, it doesn't untap during it's controllers' next untap step
-8: Target opponent gets an emblem with "Whenever a creature you control becomes tapped, this emblem deals 3 damage to that creature."