If I use a LV. 100 Pokemon in competitive, would it retain its current EVs at LV. 100?

Question

Like when they are set to level 50. Because I want to use the upcoming event shiny Xerneas and Yveltal for Battle Spot and stuff.

Answer 1

It would have the same EVs but the base stats would be reduced to as they would be when the Pokemon is Level 50.

Source: Experience and heard it somewhere.

Comments

Thanks, and also, I heard somewhere that EV training is useless on LV. 100s. is that true?

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If the Pokemon is already level 100, it can't level anymore.  While EVs can be earned freely, they are not applied until the next time the Pokemon levels up.

Also because the only way to reach level 100 without filling EVs is to use 99 Rare Candies or the daycare, because all battle EXP also gives EVs.  The raw amount of EXP you need to level at high levels makes it highly unlikely you would have EVs left to gain.