I've always wanted to do a challenging run in Reborn. Unfortunately it's NOT going to be a Nuzlocke (because I'm probably not skilled enough to do one lol). I came up with rules of my own, and here there are:
*RULES*
1. Members of the 'main team' are chosen via RNG. The starter Pokemon is also decided via this method.
2. Each member is designated an EV spread in three stats only.
3. The 'main team' members can only defeat a trainer's Pokemon if that Pokemon gives out an EV in a stat which the member is designated to have. This also applies to double battles. If this rule is not followed by mistake, soft-reset the game. This rule continues even if all the main team members have received max EVs.
4. If more than one member qualifies for a particular stat EV, the member with the lowest level has to be the one that defeats the opponent's Pokemon. If the members are at the same level, either of the Pokemon can defeat the Pokemon.
5. Until the team of full six members are assembled, up to 3 'dummy' Pokemon can be used. These Pokemon can be used in battles when the opponent sends out a Pokemon which gives out an EV stat that is not applicable to any of the current main team members. Except for the first dummy Pokemon, the rest of the dummy Pokemon has to be shiny. Dummy Pokemon can be replaced at any time.
6. No grinding of the main team is allowed, but dummy Pokemon can undergo grinding.
I'm terrible at explaining things... so I'll try to clear it up by giving an example. Say my starter Pokemon is a Mudkip, and I have given Mudkip an EV spread of 252 Atk / 4 Def / 252 Spe. The only Pokemon my Mudkip can defeat are those that give out EVs in Attack, Defense or Speed (e.g Ekans, Shinx etc.). It can still participate in a battle with a Pokemon that doesn't give out EVs in those stats, but it cannot earn any experience from it (ie it has to faint).
To defeat Pokemon that gives out EVs in Special Attack, HP and Special Defense (e.g Roserade, Bidoof etc.), a dummy Pokemon has to be used.
Additionally, if my Mudkip has earned 4 EVs in defense by defeating 4 Geodudes for example, my Mudkip cannot earn any more EVs in defense.
Lastly, if I have a Level 14 Mudkip and a Level 13 Shinx as my main team members, and they both have designated EVs in attack, my Shinx has to be the one that claims the EV when I come across a Pokemon that gives out EVs in attack.
I hope that makes it clear! Wish me luck!