Rule 608.2f

Some spells and abilities include actions taken on multiple players and/or objects. In most cases, each such action is processed simultaneously. If the action can’t be processed simultaneously, it’s instead processed considering each affected player or object individually. APNAP order is used to make the primary determination of the order of those actions. Secondarily, if the action is to be taken on both a player and an object they control or on multiple objects controlled by the same player, the player who controls the resolving spell or ability chooses the relative order of those actions. Example: Blatant Thievery says “For each opponent, gain control of target permanent that player controls.” As Blatant Thievery resolves, its controller gains control of all permanents chosen as targets simultaneously. Example: Soulfire Eruption says, in part, “Choose any number of target creatures, planeswalkers, and/or players. For each of them, exile the top card of your library, then Soulfire Eruption deals damage equal to that card’s mana value to that permanent or player.” A player casts Soulfire Eruption targeting an opponent and a creature that opponent controls. As Soulfire Eruption resolves, the player can’t exile the top card of their library multiple times at the same time, so they first choose which target they are considering, then they exile the top card of their library, and finally Soulfire Eruption deals damage to that target. They then repeat this process for the remaining target.