The Commander is described as having a "heart of stone", an unshakable resolve, complete confidence and an iron will. This is something of a misnomer, as he is in fact passionate, though it has mainly been shown through his want for vengeance at those he cared for being killed. During Shadow the Hedgehog he is determined and willing to sacrifice anything to stop Shadow and the Black Arms, but mainly the former.

In Sonic Chronicles: The Dark Brotherhood, the Commander shows another side of personality, presumably due to the different situation. Here, he shows himself as a basic military leader, stoic, wanting to get straight to the mission, dealing only with facts and ordering civilians around like soldiers. He does seem to show appreciation for those who do good work and confidence in those with a good reputation.

He is voiced by Marc Thompson, here is an example of his voice: 

https://youtu.be/wFOk1kqKd4U?t=614