Gargauth

Gargauth (pronounced GAR-goth ), or The Lord Who Watches, is the lawful evil demigod of betrayal, cruelty, political corruption and powerbrokers. He embodies the inevitable decay and corruption that accompanies all self-serving, greedy, and power-hungry leaders and groups. Gargauth holds to the letter of any agreement, not the spirit, and relishes betraying anyone with whom he forges a pact by twisting the contract to serve his own ends.

Worshipers
The church of Gargauth is a secretive faith, although there are some significant exceptions. Clerics work to increase their personal power, the power of the church, and by extension, the power of Gargauth; they are expected to be Gargauth's eyes and ears throughout Faerûn. They are to entice and corrupt powerful individuals and leaders in communities throughout Faerûn and bind them into strict contracts favorable to Gargauth's goals. They seek to seize positions of power whenever possible and integrate their positions into the secretive hierarchy of the faith. Gargauth has directed his followers to undermine other evil faiths and steal their worshipers rather than waste energy in conflicts with good deities. Clerics of Gargauth pray for their spells at dusk, when night first begins to corrupt the day. Gargauth's clergy mark all agreements with signed contracts consecrated in the name of the Lord Who Watches. Many clerics multi-class as divine disciples or sorcerers.

Holy Days
This occurs each Midwinter night. This horrific ceremony, believed to involve many gruesome sacrifices, heralds the imminent time when Gargauth shall seize Faerûn as his unholy kingdom and transport it to Baator to form the Tenth Pit of Hell.
 * The Unveiling :

This is celebrated on the eve of the Feast of the Moon. It is a personal ritual in which each cleric renews his eternal contract with Gargauth, trading absolute fealty for increased power. This unholy ritual is believed to involve personal sacrifices of money, magic, and hoarded knowledge and the casting of many horrific spells.
 * The Binding :

Relationships
Gargauth is opposed to evil deities such as Cyric and Shar. He poses a particular threat to Siamorphe, given his interest in corrupting those who she holds up as shining paragons of virtue.

Gargauth sometimes employs a powerful blue dragon named Rathguul as a steed.

History
Gargauth is a former arch-devil whose foul nature was too much even for others of his ilk. Exiled from the Nine Hells, Gargauth took to wandering the planes, returning time and again to Toril.