Stuck on 2nd Gardevoir battle

[Throhdown]

So I've progressed to the game where I've reached the 2nd Gardevoir battle and I'm firmly stuck at this part.I can't seem to beat her as she's faster than all my mons and has three shields as well as two methods of healing herself.The last time I was stuck this bad was with Angie but at the very least I could leave and change up my team with freshly caught pokemon.Anybody know a good way to beat this thing?

 

 

[Leroyyyyy]

You can try using the sylveon you got from ren to set up misty terrain which helps with sleep. Also maybe you have a mon that has memento to lower its stats.

 

Gardevoir ability dosen't really heal her that much so I don't think you have to worry about that to much. 

 

You also should try setting up trick room since I tried to paralyze and she had a lum berry and still somehow outsped me.

 

 

[Dicleon]

First, if you didn't check, she isn't psy, she's dark/Fairy, if your issue is speed then i recommend the use of tailwind talonflame, from then on detroying her shield shouldn't be an issue, she's weak to fairy, Steel, and Poison a Nostenfer with Cross poison will kick her ass once the shield are down, also as always throw your profile avatar is amazing don't hesitate to Wide guard her, i don't think she can OS it, (I think it's a double battle, might be wrong)

Edited August 3, 2021 by Dicleon

[Cyphre]

Lord Pyukumuku is your god in this fight if this is the one im thinking. He can cleanse the field with Purify, making Lovely Kiss much less of an issue. After he cleanse the arena he can use Memento, which will ease the fight a lot. 

[Throhdown]

Finally beat her!Thank God!You've all been a wonderful help <3