A nuzlocke is a difficult Pokemon challenge. At the most basic level, nuzlocke rules mean if a Pokemon faints, it's gone forever.
This is a custom mod of Pokemon FireRed/LeafGreen made by Atsign. It's randomized as well. The mod will not be posted publicly, because Nintendo.
Atsign made the mod Jordanos made the trainer sprites MikaMiba made the logo Fabian made the website and Kat and Abby helped with all these :)
A rental team will be picked for them by pChal and the other coaches. You do not want a rental team. Seriously.
They are more experienced Pokemon experts who can help players strategize & learn the rules of the nuzlocke. They can't help during battles (trainer AND wild Pokemon) though.