MajinPhil jokingly describes himself as your "friendly neighbourhood masochist" on his YouTube page, and looking at his history of challenge runs, it's easy to see why. He 100%ed The Legend of Zelda: Majora's Mask without taking a single hit in 2024, and then beat a completely randomized version of the game hitless in 2025. The next logical step, it seems, was doing the same with an Ocarina of Time randomizer.
Randomizers are mods that shuffle the locations of enemies and items within a game. They offer a challenge similar to speedrunning, where a player's knowledge and mastery of a classic game is put to the test – in this case, it's just tested in a completely different way with every run. Typically, a randomizer has some built-in safeguards to keep the game from being completely unwinnable, but beyond that, it's all fair game.