Rulings

• You must choose two targets. You can't cast Victimize targeting only one creature card.2020-11-10
• If one of the targeted creature cards is an illegal target (for instance, because it has left your graveyard before Victimize resolves), you'll still sacrifice a creature and put the other card onto the battlefield. If both are illegal targets, Victimize won't resolve. You won't sacrifice a creature.2020-11-10
• The creature you sacrifice isn't chosen until Victimize resolves. You can't return the creature you sacrifice because it will still be on the battlefield at the time targets are chosen.2020-11-10
• As Victimize resolves, you must sacrifice a creature if able. You can't change your mind and choose not to sacrifice anything.2020-11-10