Hisuian Decidueye - Solo - 7 Star Torterra Raid - Pokemon Scarlet/Violet

Rating: 9/10. No NPC requirements. Build details in description.

Decidueye-Hisui @ Shell Bell
Ability: Overgrow
Tera Type: Grass
EVs: 68 HP / 252 Def / 188 SpA
Bold Nature
Giga Drain
Nasty Plot
Grass Knot
Haze

Vitamins: 6 HP Up (or Health Mochi), 25 Iron (or Resist Mochi), 18 Calcium (or Genius Mochi)
Feathers: 8 Health Feathers, 2 Resist Feathers, 8 Genius Feathers

Stats at lvl 100 w/ perfect IVs:
HP : 334
Defense : 284
Sp.Atk.: 273
Sp.Def.: 226
Speed : 156

NPC Advantages: no requirements. intimidators (tauros, staraptor, arcanine), gardevoir (life dew), dudunspace (glare), and arboliva (seed sower) help.

Strategy: haze. terastalize on the first attack once the orb is charged. giga drain until your stats reset, nasty plot, giga drain until torterra resets its stats and uses shell smash a 2nd time. haze. giga drain when you need HP. 3x nasty plot. grass knot to victory.

Notes: physical hisuian decidueye with swords dance, leaf blade, and roost/synthesis, keeping haze, should work. on the special build if you drop grass knot and swap shell bell for metronome, it frees up a move slot for grassy terrain.

Pros: supereffective tera type matching base type, decent HP and special defense stats, great defense and special attack stats, outspeeds torterra. resists earthquake, earth power, and wood hammer. no weaknesses. haze wipes all of torterra's stat buffs from shell smash. nasty plot buffs special attack 2 stages. grass knot and giga drain have 100 accuracy and deals supereffective STAB (tera-boosted when terastalized) damage. both get a 1.5x boost from overgrow ability when HP is below 1/3 of max. grass knot has 120 base power due to torterra's heavy weight. giga drain has 75 base power and heals an amount equal to 50% of damage dealt. shell bell heals when attacking an amount equal to 1/8 of damage dealt.

Cons: haze wipes decidueye's special attack buffs as well as the -1 special defense stage from torterra's 2nd shell smash.