Let's talk about EVs. As you may know, EV training is not something that usually needs to be done in nuzlockes, as in most games the enemy trainers have no EVs whatsoever in their teams, which would give you an unfair advantage if you did, not to mention the grind.
There is one exception to this, though. In gen VII, specifically USUM, every major story trainer is EV trained, with near perfect IVs and sometimes, even favorable nature to boot:
https://pastebin.com/9WdFYnLiWhich in turn makes it acceptable to EV train in those games (in my opinion). USUM also actually gives you the opportunity to do it risk-free as you get infinite BP by doing the Mantine Surf minigame once you reach Akala Island, which you can then exchange for vitamins per 2 BP each, among other things.
Now comes my question, in the case of EV spreads for nuzlockes and considering you will have to use suboptimal Pokémon sometimes, is it better in general to EV train like in competitive, maximizing speed and offenses, or is it better to put some Evs in defenses to improve survivability, depending on your Pokémon's nature?
For example, what would be the best EV spread for this lucky Drowzee? Would it be better to maximize its defense due to its nature? Would it be worth it to put some EVs into speed, considering most trainers in USUM are fully EV trained in speed?