There are 5 models: Attacker and 4 enemy models (Defender and 3 other models (A, B, C) with 1 wound each).
The Attacker attack the Defender and deal damage with . Models A, B, C are under Marker and should be damaged.
Model A has Demise(Explosive) and Models B and C in 2" from Model A.
The owner of enemy models choose to resolve damage on Model A first.
In step 6.a. of Damage Timing Demise should be resolved.
After resolve damage timing of Model A, Demise should deal damage to Models B and C.
Question: who kills Models B and C (Attacker or Model A) and why?
P.S. A similar situation can occur with and Shockwave, Black Blood and other abilities, that deal damage after suffering damage.