For those who want to take their Pokémon journeys to the next level, the Nuzlocke challenge is a permadeath playthrough wherein a Pokémon that faints is considered "dead" and must be released. This can make the series' challenges even more difficult, though not every Pokémon game is equally difficult to complete.
Source:https://www.cbr.com/pokemon-games-ranked-nuzlocke-difficulty/