For anybody who wants to know what patrons there might get for the great old one warlocks in BG3 here is the full list of them
Ityak-Ortheel, the Elf-Eater
Dendar, the Night Serpent
Borem of the Lake of Boiling Mud
Kezef, the Chaos Hound
Zargon, the Returner
Carmnod, the Unseen
Holashner, the Hunger Below
Piscaethces, the the Blood Queen
Hhothotugg, the Eater of Worlds
Y'chak, the Violet Flame
Bolothamogg, Who Watches from Beyond the Stars
Hargut, of the Gray Pestilence
Haask, the Voice of Hargut
Ragnorra, the Mother of Monsters
The Hulks of Zoretha
Kyuss, the Worm That Walks
Tharizdun, the Elder Elemental Eye
Atropus, the World Born Dead
Pandorym, the Utter Annihilation
Haemnathuun, the Blood lord
Maram of the Great Spear
Tyranthraxus, the Flamed One
The Queen of Chaos
Father Llymic, the Alien Thought Given Flesh
Zargon, the Returner
Ghaunadaur, That Which Lurks
I love that Tyranthraxus might be a choice, it would be an amazing call back to Pool of Radiance and its sequels. I mean folks are expecting call backs to BG1&2, but having one big one for Pool of Radiance would be awesome as well.
I'm also fond of Atropus, an Atropal that is the size of an evil moon, immune to divine magic, last seen waging war against Glyph, the Mindflayer world in Realmspace. Atropal could be the thing that even the Mindflayers are afraid of and the big bad of BG4.
Pandorym, who was the Imaskari nuclear option, who they split into two parts, his mind and his body. He was meant to protect them from the Mulan Gods, but the Imaskar seemed to decide that having their nation destroyed was preferable unleashing something that was dangerous to the material plane itself.
Haask, the Voice of Hargut (who is an ancient Batrachi Lord (of the Doppelganger variety), who used to rule over a Minotaur Kindgom until the Dead Three fused him to the Elder Evil Hargut.
Tharizidun is the source of the Abyssal Plague that effected multiple worlds inclusing Nerath, Toril, and Athas.
Maram of the Lost Spear is said to be one of the Seven Lost Gods.
Ragnorra is an Al Qadim Goddess, which is set to the South East of Faerun in Zakhara. So this is the Second Deity/Elder Evil.
Kyuss really belongs in Greyhawk, he has no connection that I know if to Toril or Realmspace.
Piscaethces, the Blood Queen is also a God I believe.
Dendar is certain to be in if Yuan Ti Purebloods are.
