Height: 191 cm (6'2")

Birthday: December 14

A 21-year-old ace pilot who focuses solely on his duty as a member of Delta Platoon. Because of his serious nature, he has a distrust for Hayate's carefree attitude. Despite their differences, Hayate admires Messer's flying style.

Messer was a resident of the town of Marienburg (マリエンブルグ) on the planet Alfheim (惑星アルブヘイム) before it was wiped out by the Var Syndrome. Arad had saved him; however, he had already been infected with the Var Syndrome. He suppresses it with a bracelet that plays the song "AXIA" by Kaname. He has feelings for Kaname, even though he knew she liked Arad.

Messer's Siegfried unit, Δ02, is colored in a white, black, and gray scheme and has a Grim Reaper marking on its back—matching his nickname as the Grim Reaper.