Each of your opponent's Characters loses Stun and can't use Ambush.
Disrupt a Trap.
INSERT: Tap one of your opponent's Neutral Characters. Play only during your build step.
Keywords
Ambush
Ambush X: A layered, activated ability that means, "If your opponent deploys, moves, or puts a unit into this arena, this unit does X dice of damage to that unit." Each Ambush can be used once per instance of a unit being deployed, moved, or put.
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.
Stun
Stun X: A cumulative ability triggered during the damage placement POP that means, "When this unit damages another unit, that unit gets –X power until end of battle." If no damage counters are placed as a result of damage, Stun doesn't occur. Stun works anytime the unit damages another unit, not just when it attacks. Only the unit with both Deflect and Stun abilities can stun when it activates its Deflect.