Xiahou Dun

Xiahou Dun (夏侯惇) is the Guardian Spirit of Cao Yan Bing.

Techniques
Mountain of Knives:

Spirit Army Arc
Xiahou Dun is introduced along side Xiahou Yuan. When Cao Yan Bing asks them to comply with him to aide him in his battle.

Trivia

 * Xiahou Dun is based upon the historical figure of the same name.