For the base effect of "Instruments of Their Own Ruin," if there are multiple Invaders with Strife, do they deal Damage simultaneously? Can they deal Damage to each other?
For the base effect of "Instruments of Their Own Ruin," if there are multiple Invaders with Strife, do they deal Damage simultaneously? Can they deal Damage to each other?
Yes and yes.
So if you had a City, a Town, and an Explorer all with Strife, the Town + Explorer could destroy the City while the City destroyed the Town + Explorer.
The same applies to the Terror Level III effects of the Fear cards "Discord" and "Theological Strife," and to the "Afflict with Bloodthirst" Innate Power of Wounded Waters Taste of Ruin.