WotC's Mearls talks to D&D Beyond about the Warlock Celestial subclass in Xanathar's Guide to Everything. "What we've established in the cosmology of Dungeons & Dragons, is that clerics are tied to the divine beings, gods, or concepts and viewed with the divine, so it might be like the silver flame from Eberron. The celestial though is rather than being a divine being per se, it's a celestial being so it could be something like an angel, a ki-rin, a unicorn or anything else that's a powerful good aligned creature but it doesn't necessarily have to be a God."
[video=youtube;yfEWMNe2Q8M]https://www.youtube.com/watch?v=yfEWMNe2Q8M[/video]
"And so that's the difference between for a warlock, warlock don't make pacts with specific individuals who are sharing power with the Warlock, rather than a cleric renting, gains power that's granted to them by the divine. And also with Celestials we still assume obviously it's a celestial, it's some sort of good aligned creature. So it's something the celestial warlock compared to other warlocks as a healer, they gain cure wounds as one of their sort of baked-in first level spells, and one of their first class class features allows them to heal. They also deal with radiant energy.
So I mean obviously you can play an evil celestial pact warlock if you wanted to, nothing stopping you from doing that, but the game kind of assumes that celestial means either good aligned or having to do with radiant energy and healing. And so compared to a cleric, where when you think of a divine spellcaster you think you think they're going to be tied to a domain like the cleric class does, where the god's portfolio influences the follower's magic, the celestial's more specific about being about radiant energy. It's almost like it's less refined compared to a cleric's ability to wield magic and cosmologically it's more of a brute force way to get magic with a pact, and that's kinda how we think of the Warlock in general that the Warlock pact is like the is almost like a a hack in the system of magic rather than the sort of accepted or intended ways in which people use spells. And in my head canon that's kind of why the warlock came into D&D later on it, sort of took the universe of D&D a while, people to figure out how to use magic this way as opposed to the sort of more traditional spell slot based ways of using magic.
And so yeah it's a celestial, you can imagine it might be something like especially, say, a coatl who might have agents in the world and so the coatl has these pacts with its agents for going out and working on its behalf, so they're they're good aligned celestial style creatures who aren't gods. And because of that one of the things I like about warlocks [in the city of pax?] is it can be more personal, a coatl might have a desire to protect a specific person, a specific family, or city where gods are more remote in Dungeons & Dragons, and I think that's something which in a DM can play up or a player could really bring into the game, this idea that the patron is more personal, might be someone you have more direct conversations with rather than speaking directly to God or Thor or something like that where they're much more remote, more abstract.
So I really kind of created it with this idea of someone wanting playing more the heroic warlock. Warlocks traditionally have a sinister bent to them in the game. If you look at the Players Handbook, the initial patrons are either things that are traditionally very evil like a fiend or the Great Old Ones or something that's kind of dangerous, maybe not evil but not necessarily friendly like a fey lord, so we wanted to kind of balance the scales a little bit and say being a warlock is does not inherently make you villainous or doesn't inherently make you dark and sinister. That celestial beings - obviously it's a celestial pact - they can also create pacts and so it's kind of balancing out the storytelling possibilities. And I also like that even introducing a new healer into the game essentially then you can run a warlock as your healer if you don't want to play a cleric, you can play a character in a very different casting tempo who can still bring a lot of healing to the table for the group."
[video=youtube;yfEWMNe2Q8M]https://www.youtube.com/watch?v=yfEWMNe2Q8M[/video]
"And so that's the difference between for a warlock, warlock don't make pacts with specific individuals who are sharing power with the Warlock, rather than a cleric renting, gains power that's granted to them by the divine. And also with Celestials we still assume obviously it's a celestial, it's some sort of good aligned creature. So it's something the celestial warlock compared to other warlocks as a healer, they gain cure wounds as one of their sort of baked-in first level spells, and one of their first class class features allows them to heal. They also deal with radiant energy.
So I mean obviously you can play an evil celestial pact warlock if you wanted to, nothing stopping you from doing that, but the game kind of assumes that celestial means either good aligned or having to do with radiant energy and healing. And so compared to a cleric, where when you think of a divine spellcaster you think you think they're going to be tied to a domain like the cleric class does, where the god's portfolio influences the follower's magic, the celestial's more specific about being about radiant energy. It's almost like it's less refined compared to a cleric's ability to wield magic and cosmologically it's more of a brute force way to get magic with a pact, and that's kinda how we think of the Warlock in general that the Warlock pact is like the is almost like a a hack in the system of magic rather than the sort of accepted or intended ways in which people use spells. And in my head canon that's kind of why the warlock came into D&D later on it, sort of took the universe of D&D a while, people to figure out how to use magic this way as opposed to the sort of more traditional spell slot based ways of using magic.
And so yeah it's a celestial, you can imagine it might be something like especially, say, a coatl who might have agents in the world and so the coatl has these pacts with its agents for going out and working on its behalf, so they're they're good aligned celestial style creatures who aren't gods. And because of that one of the things I like about warlocks [in the city of pax?] is it can be more personal, a coatl might have a desire to protect a specific person, a specific family, or city where gods are more remote in Dungeons & Dragons, and I think that's something which in a DM can play up or a player could really bring into the game, this idea that the patron is more personal, might be someone you have more direct conversations with rather than speaking directly to God or Thor or something like that where they're much more remote, more abstract.
So I really kind of created it with this idea of someone wanting playing more the heroic warlock. Warlocks traditionally have a sinister bent to them in the game. If you look at the Players Handbook, the initial patrons are either things that are traditionally very evil like a fiend or the Great Old Ones or something that's kind of dangerous, maybe not evil but not necessarily friendly like a fey lord, so we wanted to kind of balance the scales a little bit and say being a warlock is does not inherently make you villainous or doesn't inherently make you dark and sinister. That celestial beings - obviously it's a celestial pact - they can also create pacts and so it's kind of balancing out the storytelling possibilities. And I also like that even introducing a new healer into the game essentially then you can run a warlock as your healer if you don't want to play a cleric, you can play a character in a very different casting tempo who can still bring a lot of healing to the table for the group."
