Scizor

[[Scizor, the Pincer Pokemon. Bug/Steel.]]

[[It uses its wings to adjust its body temperature. Otherwise, its metal body would become too hot and melt in the heat of battle.]]

Efficient! Fierce and elegant, and a perfect way to end my search.

(6/6, not accepting more!)

Mawile, Steel/Fairy
Hydreigon, Dragon/Dark
Aggron, Steel/Ground
Metagross, Steel/Psychic
Bisharp, Steel/Dark
Scizor, Bug/Steel

Almost exclusively Steel-types, and the Dragon to protect them all from their weaknesses. Perfect.