As long as Darth Nihilus is in any arena, Nihilus's Ravager gets Armor.
INSERT: Pay 1 Force Evade 1
Keywords
Armor
Armor: An isolated, static ability that means, "This unit can only be hit on a roll of 5 or more." Armor works against dice of damage and attack dice. It redefines what die roll is required to hit a unit. It doesn’t modify the die roll like Accuracy. A unit with Accuracy 1 attacking a unit with Armor hits with 4's, 5's, and 6's.
Evade
Evade X: A layered ability activated during the damage prevention POP that means, "Prevent up to X damage to this unit." You can play Evade only once for each instance of damage. You don't have to use all of the Evade. You choose how much damage to Evade up to X, even if the full amount of damage or more is pending.
Hidden Cost
Hidden Cost X: A selective, static effect that means, "As long as you have a number of build counters on this card equal to X or the unit's current build cost (whichever is less), you may complete it anytime by paying Force for the remaining build cost, if any." Effects and stacking rules may reduce the build cost. You do not need to pay Force if the build cost is within the Hidden Cost integer. You can deploy it to the build zone. Hidden cost can only be played if the card is partially built and has the required number of build counters on it. You may use Hidden cost anytime, even during any Play-or-Pass chances not reserved for re-roll, damage prevention, or disrupt POP chances. If there are a number of build counters on the unit equal to or greater than the Hidden Cost integer, you do not need to pay any Force. You may not use Hidden Cost to deploy a Pilot to a unit.
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.
Upkeep
Upkeep: [Cost]: A layered ability triggered when the build step starts that means, "When the build step starts each turn, you must pay the following cost." You must choose one of the costs that you can pay each turn, and ignore the others. You must still pay the Upkeep costs of a unit even if that unit is in the build zone, becomes the top card of a unique unit stack, or Pilots another unit. The Upkeep must be paid if you can pay it. If you can't pay any of the listed costs in full, then ignore Upkeep. If a unit has multiple Upkeep abilities, fulfilling just one of the Upkeep abilities (such as tapping the unit) does not satisfy all the Upkeep costs at once; it would only satisfy that instance of Upkeep. You may choose the order of multiple Upkeep abilities to keep an Upkeep from being paid, though a different order might pay it.