>>306225041: They changed how rare candies work a couple generations ago- you can now EV train at level 100, so nothing is 'locked'
2: define 'viable'. if you're looking for in-game, almost anything works. If you more mean the competitive aspect of it all- see: Smogon's tiers (in which you can find whatever format that suits you (and/or your favorite pokemon) best).
3: the higher the IV, the better. Almost all competitive pokes are 5IV (meaning x5 31s, maybe a 30 or two at lowest). Natures depend on what you're doing- for Lycanroc I'd say you really only want to attack, which requires the attack stat you choose, and /or speed.
The 'Big Four' for sweepers are:
Timid(+Spe -Atk) & Modest(+SpA -Atk) for special attackers
&
Jolly(+Spe -SpA) & Adamant(+Atk -SpA) for physical attackers.
Did that help, anon?
