Relentless (C)

Keywords

Avenge

Avenge X: A cumulative, triggered ability that means, "Whenever damage from an attacking unit causes one of your other units in the same arena as this unit to be discarded, this unit does X dice of damage to the attacking unit when the attack ends."

INSERT

INSERT: A layered, static ability that means, "When this card is in play or stacked under the unit, the unit gets the following effect:" Insert works while in the build zone. The effect works while anywhere in the unit's stack. The granted ability remains to be the ability of its type. (For example, activated abilities granted by Insert may be disrupted.) The granted effect may not work in the build zone as per the rule for the rule for that effect.

Resilience

Resilience X: A cumulative, static ability that means, "As long as this unit has at least X damage counters on it, it gets +X power."

Shields

Shields X: A cumulative, static ability that means, "The attacking unit gets –X power against this unit." Shields only matters when attack dice are rolled. If you give a unit Shields after your opponent has rolled for damage, it doesn't affect the roll.