Asmodeus

Asmodeus was the a general for the gods against the demons of the Abyss during the Dawn War. As he fought his troops gradually began to show signs of corruption. Their new appearances displeased the gods, so Asmodeus petitioned them to create a place where he could keep the demons hordes at bay and keep his troops from the god's sight. They consented and created what we now know as the Nine Hells.
Asmodeus then petitioned the gods to allow him to replenish the numbers of his troops from mortals. He promised to do this only to willing individuals, and the gods allowed this, signing a contract written by Asmodeus himself.
When it was discovered that the souls being used weren't being sent on to their appropriate afterlives, the gods dragged Asmodeus to a trial before Bahamut. The trial was incredibly one sided, with the gods and their angels ganging up on Asmodeus. When finally Asmodeus was asked to defend himself, he said only one sentence: Read the fine print.
Caught by their own obligations, the gods bound Asmodeus to follow his contracts exactly and to leave nothing out. To bind him, they gave him a staff carved from a single ruby and threw him sealed him in the Nine Hells.
I heard this story from a follower of Asmodeus, shortly before his execution. Something about this story feels off, but it has been coroborated by followers of other gods under the effects of a Zone of Truth.

From the Notes of Lady Rhewa of House Alt'mer
Dated the 17th Adamant, 124

Divine Domains

Treason, Sin, Corruption

Divine Symbols & Sigils

A triangular spear head, seperated into three parts

Tenets of Faith

Youth and innocence demand corruption.
Ambition and greed are natural.
Ambition and greed are natural.
Exploit every weakness.
Destroy that which cannot be corrupted.

Divine Classification

Deity

Alignment

Lawful Evil

Honorary & Occupational Titles

The Betrayer, Prince of Nessus, Ruler of the Nine Hells, Hell’s Wrath, Overlord of Hell, Lord of Vengeance

Current Residence

Malsheen, Nessus, the Nine Hells

Gender

Male