I've been reviewing some 3E material.
The module Speaker in Dreams has infernal clerics. They are expressly said to worship Hextor, but are also described as a diabolical cult (p 18). When they take over the temple of Pelor, it "now smolders with hellfire" (p 22). Nothing about the module would need to change if instead they were worshippers of Asmodeus. I don't think infernal pact warlocks would fit as well.
The module Bastion of Broken Souls has a 12th level cleric of Tiamat, "a human cleric of the evil dragon deity Tiamat" (p 28). This character has a full suite of spells for her level. Tiamat is not mentioned in the list of default gods in the 3E PHB. She is statted up in a sidebar on p 118 of the 3E MotP, but there is no reference to her being a god. Then, in the later-published 3E DDG, she is presented as a god in the default pantheon, with a stat block that is the same as the MotP one in some parts (eg hit points, damage) but different in others (eg AC, to hit bonuses, skill bonuses).
This variability across the space of three years of material (publication dates 2000 to 2002) is a microcosm of the different approaches across the lifetime of the game.
The module Speaker in Dreams has infernal clerics. They are expressly said to worship Hextor, but are also described as a diabolical cult (p 18). When they take over the temple of Pelor, it "now smolders with hellfire" (p 22). Nothing about the module would need to change if instead they were worshippers of Asmodeus. I don't think infernal pact warlocks would fit as well.
The module Bastion of Broken Souls has a 12th level cleric of Tiamat, "a human cleric of the evil dragon deity Tiamat" (p 28). This character has a full suite of spells for her level. Tiamat is not mentioned in the list of default gods in the 3E PHB. She is statted up in a sidebar on p 118 of the 3E MotP, but there is no reference to her being a god. Then, in the later-published 3E DDG, she is presented as a god in the default pantheon, with a stat block that is the same as the MotP one in some parts (eg hit points, damage) but different in others (eg AC, to hit bonuses, skill bonuses).
This variability across the space of three years of material (publication dates 2000 to 2002) is a microcosm of the different approaches across the lifetime of the game.