basically reactive abilities, but you pre-pay for them and select targets at the time of "setting". The identity remains hidden in the support zone, but your opponent can see that a trap has been set. Targets couldn't be tracked this way in a physical ccg, but infinity wars is a ccg like no other. Technology can track hidden game states such as targets set without your opponent knowing, and i think we'd all be missing out if the design space didn't get used. Furthermore, because these abilities trigger on events, they can blend quite nicely into the initiative system and make it much less "me first, then you"
Mine Field (factionless) [trigger mine field the next time a character attacks you. mine field deals 2 damage to each creature in your opponents attack zone]
Geosat bomb (genesis) [Target character on the battlefield. when targeted character moves to the support zone, trigger geosat bomb. destroy targeted character and deal damage equal to that character's power to other support zone characters.]
Thickened Skin (warpath) [target character you control. triggers when targeted character would be dealt damage by an ability your opponent controls or combat. prevent damage taht would be dealt to targetted creature this turn]
Death's embrace (verore [triggers when a character you control dies. You gain morale instead of losing morale when that character dies. Characters you control get +1/+1 for each character that dies this turn.
Sear (flame dawn) [target a character you control. triggers when target character you control deals damage to an enemy character. the enemy character that was dealt damage becomes immolated
Indomitable Will (DoD) [target a character you control. triggers when targetted character is dealt combat damage or would be killed by an ability. targetted character becomes invincible until end of turn]
[edit: just noticed i'd submitted the same idea much earlier, but without going into detail. apologies for the repeat]