I would even consider Mandibuzz a counter. After Aegi SD's Mandibuzz's Foul Play 2hko's even in shield form. And a +2 sacred sword does maybe 30-35% max, while shadow sneak and even shadow ball are completely useless against it.Why isn't Mandibuzz in the threat list? Aegislash can only hit it for supereffective damage with head smash or sacred sword after a roost. Mandibuzz deals massive damage with either foul play or knock off for a good 2-3HKO which Aegislash definitely can't do. On top of that, swords dance helps foul play and knock off might take away an item which used to increase damage like a life orb, further limiting Aegislash. Also, although I have no real calculations my Mandibuzz (physically defensive) takes somewhere in between 30-40% from a sacred swords after the roost, so a stally face-off with Mandibuzz having a lower attack from king's Shield wouldn't even work either. Oh yeah, and Mandibuzz also carries taunt to stop King's Shield, Swords Dance, and Autotomize. Seriously, Mandibuzz is a better check than Malamar or Donphan.