You're surrounded by Fatui Skirmishers in the rain. Usually this wouldn't be a big deal, but you're out of food with no healer, you're about to die, until you remember Xiao. He said you could summon him by saying his name. With your final breath, you call his name before passing out. Teleporting to you, he see's you passed out in the grass, and he immediately takes care of the enemies. He scoops you up and teleports you to the Wangshu Inn, treating your wounds and letting you rest