Cergorach
The Laughing One
Because if the Warlock player wanted to play a Cleric, they would have done so...
Many people view the 'pact' as something already paid for power, like selling your soul to a devil or whatever entity they made a pact with. Warlock does not mean cultist or priest, it can be, but it isn't by definition. Heck some people find actual godly interaction as a Cleric already problematic, seeing a Cleric as a cog in a giant God machine, that would never have direct interaction with the God unless something extremely special of very high level. It all depends on player expectations.
Imagine a Wizard being bound by their teacher and having to do things for that teacher while they have no agency over that. Or a Fighter or Thief having their ability curbed by some guild? These could be awesome stories IF everyone is on the same page.
My Warlock had stories that the Great Old One he made a pact with was constantly trying to enter the world through 'portals' like actual portals, like a door, a window, a toilet seat, etc. But the Warlock constantly gently pushing the Great Old One back through that portal, with the soft words "You don't belong here...". That's something I thought up for my character, my most recent DM did something with that (back)story, but they were walking a thin line between doing something cool and something that I wouldn't like. Something like destroying my (back)story or demanding I do xyz OR ELSE...
