Why is this Blissey not useable in free battles?!

Question

Okay so I powersaved this Blissey for use in free battles and from what I can tell it all checks out, so could someone steer me right, since I am wrong?

Blissey @ Leftovers
252 Hp/252 Def/6 Spe
All IV’s are 31
Natural Cure
Docile Nature
714 Hp/56 Atk/119 Def/186 SpA/306 SpD/147 Spe

Wish
Protect
Seismic Toss
Toxic

Comments

Blissey can only learn wish in Generation 3, and Pokemon hatched in Generation 3 might not be usable in free battles.

---

That should be an answer

---

But I wasn't sure if free battles allowed event Pokemon from older generations.

Answer 1

Powersaved?
I heard that powersaved Pokemon are banned in Free Battles... that's pretty much it
SOURCE- the answer to this question https://pokemondb.net/pokebase/278910/cant-powersaved-darkrai-solgaleo-pokemon-moon-free-battles