Groznik gets Accuracy 1 and Overkill when attacking an Imperial unit.
Pay 1 Force Retaliate 3
Pay 3 Force Untap Groznik. Play only if Groznik damaged one of your opponent's Imperials this turn.
Keywords
Accuracy
Accuracy X/-X: A cumulative, static ability that means, "Add X to each of this unit’s attack dice." and "Subtract X from each of this unit’s attack dice." respectively. Accuracy can’t alter "natural" rolls to affect Critical Hit, Fury, or Parry, but it can affect your chance against Armor. If a unit gets the Accuracy ability after you roll attack dice, it's too late to affect the hits.
Overkill
Overkill: An isolated ability triggered during the pending damage POP that means, "When this unit attacks, you may divide hits in excess of the defending unit's remaining health between that unit and another unit in the same arena." The player who controls the attacking unit decides how many hits (if any) in excess of the defending unit's remaining health to reassign as damage to the second unit. (That player can't change their mind afterward.) A number of hits equal to the defending unit's health must be assigned to the defending unit, and the remainder may be assigned to the defending unit or another unit in the same arena. Overkill damage is caused by the ability, not the die roll. Shields, Parry, and Armor have no effect against it, but damage prevention not specifying dice works normally. Both units resolve damage in tandem.
Retaliate
Retaliate X: A layered ability activated during the attack POP that means, "If a unit in the same arena as this unit is attacking this unit, this unit does X dice of damage to that unit when the attack ends." A Retaliate ability without an activation cost has a printed cost of "Pay 0 Force -->". Retaliate resolves when the attack ends, even if your unit gets discarded. Retaliate dice are just dice of damage, not attack dice, and can trigger Stun. Retaliate based on a unit’s power is based on its total power at the time the Retaliate is activated. Retaliate doesn't work with attacks from another arena (such as Bombard and Ion Cannon) or the build zone. A unit may retaliate against itself if it attacks itself. Each Retaliate may be used once per attack. Each defending unit can activate Retaliate during the attack POP, which resolve in their order when the attack ends, even if the retaliating unit is discarded.