If your opponent can't boss around it constantly, H.Goodra Vstar and Gardevoir could be great, taking 3hkos from Mew and Arceus while dealing a heavy 200 damage in return. Has potential to be a frustrating wall deck if you include healing items.
Its a monster, also can completelly heal one time without mayor drawbacks, also no weakness, with the -30 damage galarian tool and -20 from Gardevoir the thing has 400 hp basically, water atack cost that can be covered with Melony and Crystal Cave to cure 30 every turn, I gonna hate face this thing...