Can I ask how galar slowking got to ou?
I saw some sets with assault vest that can tank a lot of special hits and fire back, also, Regenerator provides it with recovery that it would normally miss when it has an assault vest.
To show how extreme Slowking-Galar's SpDef after Assault Vest is:
252 SpA Choice Specs Spectrier Shadow Ball vs. 252 HP / 4 SpD Assault Vest Slowking-Galar: 260-308 (65.9 - 78.1%) -- guaranteed 2HKO
+1 252 SpA Volcarona Flamethrower vs. 252 HP / 4 SpD Assault Vest Slowking-Galar: 139-165 (35.2 - 41.8%) -- guaranteed 3HKO
252 SpA Life Orb Sheer Force Nidoking Earth Power vs. 252 HP / 4 SpD Assault Vest Slowking-Galar: 229-273 (58.1 - 69.2%) -- guaranteed 2HKO
Comparing Slowking-Galar with Blissey by using a neutral attack:
252 SpA Choice Specs Transistor Regieleki Rising Voltage (140 BP) vs. 252 HP / 4 SpD Assault Vest Slowking-Galar in Electric Terrain: 342-403 (86.8 - 102.2%) -- 18.8% chance to OHKO
252 SpA Choice Specs Transistor Regieleki Rising Voltage (140 BP) vs. 252 HP / 4 SpD Blissey in Electric Terrain: 429-505 (60 - 70.7%) -- guaranteed 2HKO
252 SpA Choice Specs Transistor Regieleki Rising Voltage (140 BP) vs. 252 HP / 252+ SpD Assault Vest Slowking-Galar in Electric Terrain: 250-295 (63.4 - 74.8%) -- guaranteed 2HKO
With max SpDef investment and a SpDef boosting nature, this thing is basically Blissey but it can hit back with 110 SpAtk and recover 33% of its HP when switching out.