Ok so I bought Emerald again and for the first time ever Im trying to nerd out and get good natures and EV training and all that stuff for the Battle Frontier. At first my Treeco had a Bold nature which decreases attack so I actually restarted until I got something to lower Sp. Attack instead. So I ended up getting Impish, which is supposed to raise Defense and lower Sp. Attack.
My question is at what level does that actually start taking effect. My Grovyle is currently at Lv. 17 and the stats are as follows:
Sp. Attack 34
Sp. Defense 31
as you can see this nature is doing the exact opposite since the stat its supposed to raise is the lowest of all of them. Does it just take a long time to actually start working? Or is it just broken?
It takes effect for level 1, 2, 3 and all the way up to 100.
The thing is, it's so much more than nature. Base Stats are fundamental to overall stats. Grovyle's base stats for HP / Atk / Def / SpA/ SpD / Spe are 50/65/45/85/65/95.
So you can see, despite Impish improving defence, it's still the lowest stat because it's base Defence stat is the lowest.
Although not related, IVs and EVs are also crucial to overall stats. They explain why your Grovyle's SpD is 3 points higher than Attack when they should be equal.