If Wayward One has summoned Warper (This minion is aligned to IV. When a player deals damage, that player must deal damage to this minion.), spells and abilities that deal split damage may still damage other targets, so long as at least 1 damage is dealt to Warper.
Example: Jian has Monstrous Inferno (Cast: Deal 7 damage divided however you choose to the nemesis and any number of minions.) prepped on her closed III and IV breaches. She casts the spell and chooses to direct 1 damage to Warper and 6 damage to Wayward One.