We currently still have only one positive status effect, Barrier. How about a status effect that grants a troop Cloaked? It’d be like hiding in shadows in other games, and could have several effects, such as:
A Cloaked troop could have its stats (health, mana pool, etc.) hidden from the opponent. On defense, that could serve to make it harder for the invading player to decide whether to target the Cloaked troop or not. On offense…well, perhaps it’d be useless
A Cloaked troop could do more damage (maybe 2x) on skull hits, or gain a temporary boost to Magic, etc.
Rogue troops could have a trait that allows them to do even more damage when Cloaked, or to allow them to hit the rear target with skulls when Cloaked, or any number of other combo effects.
In any case, Cloaked would break on the first time that troop casts a spell, matches skulls, or takes damage.