While on a deep-sea freedive, Ori encounters a cave and decides to explore it, knowing that with his absurd breathholding ability there isn't a whole lot of risk in doing so. Except, the entrance collapses, and he ends up wandering around for over an hour before finding another way out. This brought even him to his limit, and if he'd taken just a few more seconds, he would've started trying to breathe anyway!
Made by rekstone767, heavily edited by me. I've made a short story based on this, by the way!