Shadow and Bone
After they see a pretty Grisha girl go by with the Darkling's entourage, Mikhael nudges Mal and they make suggestive commentary about Mal's chances with her. He calls Alina by her hated nickname "Sticks" but otherwise ignores her.
Months later, after Alina has escaped from Os Alta and met up with Mal, he tells her that Mikhael, with their friend Dubrov, had been a part of the tracking party that the Darkling ordered to seek Morozova's Stag. During the mission, their commander had the idea of sending people over the Fjerdan border to continue the hunt. Mal volunteered, and Mikhael and Dubrov followed suit.
Out of the nine people on the hunt, only two survived. Mal says that it was his choices that "got [his] friends killed", suggesting that neither Mikhael nor Dubrov were the other survivor.
He is a large man with red hair.