Momon

Momon is the adventurer persona that Ainz Ooal Gown (the protagonist of Overlord) uses when operating in the human world of the New World.

Key points about Momon:

• He is a tall, imposing dark warrior clad in heavy black armor with a menacing helmet that completely hides his face.
• He wields two massive greatswords and is presented as an incredibly powerful adamantite-ranked adventurer (the highest rank).
• Momon is accompanied by his beautiful "adventurer partner" Narberal Gamma (who goes by "Nabe"), and they form the famous adventurer duo "Momon and Nabe" of the Swords of Darkness fame early on.
• His public image is that of a stoic, honorable, ultra-strong hero-for-hire who always accomplishes his missions and defeats powerful monsters.

In reality, "Momon" is just Ainz deliberately playing the role of a heroic adventurer to build reputation, gather information, and manipulate human society while hiding his true identity as the undead Overlord.