Tiax

"When asked about his past, Tiax ignores you entirely, preferring instead to loudly proclaim what is in store for his future. He obviously worships Cyric, but also seems to share a touch of his madness. Tiax unquestioningly believes that he is destined to rule the world, and his fervor makes him blind to the ridiculous nature of the goal. He seems harmless enough for now. "

- Character description from the Baldur's Gate computer game

Tiax was a wandering cleric of Cyric. Not nearly as mad as his god, but insane nonetheless, Tiax claims that Cyric has granted him visions of world domination and he has made it his life's mission to fulfill those visions, attempting to create a worldwide theocracy in Cyric's name. He was not very successful in this endeavour, but it did not stop him from reminding everyone who he met of his goal. Over and over again.

He met with the Protagonist in Baldur's Gate before travelling south to Amn, where he was captured by the Cowled Wizards as a 'deviant' and held in Spellhold.

When the Protagonist arrived in Spellhold, Tiax and the other inmates were released (he professed to only vaguely remember the Protagonist) in order to help attack the more powerful Irenicus. Tiax was killed in the ensuing spell battle, his dying words claiming that death was but a minor inconvenience to his plans for ruling all.

Behind the scenes
Tiax was voiced by John Mariano in in Baldur's Gate and Baldur's Gate II: Shadows of Amn

Tiax