What happens if I change the nature of a lvl 100 Pokemon?

Question

I didn't care about natures until recently. I know how to change it but if I change it at lvl 100, will all it's stats change, and will it affect it's ev?

Comments

I don't think so. In pre gen 5, you cannot ev train anymore if your pokemon is lvl 100 since the evs are added upon lvl up before it was changed in gen 5 onwards to be added after every battle.  Also, I believe natures are determined upon encountering a pokemon. Once it is caught, I don't think it's nature can even be manipulated at all

---

Savitar, in Gen 8, there were items introduced that enabled you to change natures.

Answer 1

A nature change would change stats, but not all of them, just the affected ones changing. It doesn't really matter if it's level 100.

So say you wanted to change from, say, Lax (+Def, -SDef) to Adamant (+Atk, -SAtk), those would be the only stats changing. Defense and Special Attack would go down, while Special Defense and Attack would go up. Speed was not touched in this scenario, so it will remain the same.