Matheus Johan Weiss a.k.a Matheus is the Vice Commander and 2nd Company Commander of the 203rd Aerial Mage Battalion. He was appointed vice commander by Tanya. 

He has a curved face, black hair, and eyes. He often wears his military officer suit in causal circumstances.  He is a prudent yet not unrelenting man. He is skilled at managing and is able to discipline his subordinates, making him competent at his duties. He is very concerned about his subordinates, usually taking care of the battalion in various ways and enjoying the confidence of them. 

For Tanya, he is thoughtful and reliable subordinate whom she is willing to spend much time on, She also usually chats (sometimes bickers) with him. 

For warnings in advance: In a particular episode he has a suggestive line, however, this line remains family friendly but implies something that isn't of parental guidance.

The voice actor: The voice-over talent should have a caring dad like nature. However stern.