>>23411563#1 Answer: Mandibuzz
Only ever bothered by the Toxic variant or the Head Smash variant. Considering you're catering said Mandi to stop it, run Taunt. And Head Smash is pretty rare to see but not out of the question, I think it does in the 70s damage percentage wise. Foul Play is the move of choice.
#2 Answer: Mega Charizard-Y
OHKOs virtually any Aegislash and can Roost to contend with King's Shield mind games. Only problem is the rare Head Smash on switch-in, when behind a Sub.
#3 Answer: Landorus-Incarnate
Sheer Force Life Orb Earth Power OHKOs standard set, although not as accessible on cart because of it being the HA.
#4 Answer: Bisharp
Life Orb Adamant Knock Off does minimum ~98% to the standard investment Aegislash. Only problem is switching in or having to get around a Sub, because Sacred Sword will kill.