§ 370.4 Core Rules PDF (officieel)

A Game Object can apply its Replacement Effects to any qualifying events that occur simultaneously with it leaving the zone that its Replacement Effect is active in. Example: Soraka, Wanderer has a Replacement Effect that reads, “If another unit you control here would die, if it has less Might than me, instead heal it, exhaust it, and recall it.” Soraka’s replacement can be applied to any qualifying event that occurs simultaneously with her leaving the board, including to units that die simultaneously with her.