Whenever you deploy a Remnant Stormtrooper to the Ground arena, you may pay 1 Force if you do, put 1 damage counter on one of your opponent's units in the Ground arena.
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.
Stealth
Stealth: An isolated, static ability that means, "This unit can't be attacked unless it's tapped or has damage counters on it." An untapped and undamaged unit with Stealth can still be affected by alternative types of damage. (Such as Overkill.) As long as the unit has any number of damage counters on it, it can't use Stealth.
Switch
Switch: [1st/2nd/3rd type effect]: A layered, static ability that means, "As long as this unit is in the first arena listed on its type line, it gets the effects listed to the left of the first slash. As long as this unit is in the second arena listed on its type line, it gets the effects listed to the right of the first slash. As long as this unit is in the third arena listed on its type line, if any, it gets the effects listed to the right of the second slash, if any." If it says "None" as one of the arena type's effect, it means that it gets no extra effects while in that arena. The unit's Switch effects will correspond to the types listed on the unit's type line. There won't be a slash for an arena not listed in the unit's type. Switch doesn't allow units to change arenas during the battle phase.