Some effects deal or assign Wounds without going through the attack sequence. These effects are not attacks, so no defense dice are rolled, nor are any Suppression tokens assigned. The player that controls the unit suffering Wounds assigns the Wounds as normal.
Some effects explicitly state that a certain miniature in a unit suffers Wounds. In this case, the player who controls the effect may assign any Wounds suffered in this way, ignoring the normal rules for assigning Wounds.