^ I think that is how it will work as well, it clearly says once the model is slain. That to me means theres no wounds hovering waiting for it to come back, you assign wounds and it dies, then is essentially summoned again with 1 wound remaining.
Once a model is slain is it not dead? I don't really understand how you could RAI that differently.
Also cycle of storm is not something that is "triggered" the player chooses when to use this ability and on what target. It is not something that you even need to declare before the wounds are assigned.