Are there drow deities that encourage cooperation with surface elves, and possibly reunion / conquer?

Question

Inspired by How do I encourage Drow players to not make Drizzt clones?

I'd love the concept of truly evil drow cleric adventuring on the surface and trying to cooperate with surface elves, hating their soft, cowardly ways (aka not being merciless selfish bastards). I vaguely remember there used to be a god in the drow pantheon just about that, but I can't find any reliable source on him.

So what was this god, where is he described, and does it exist in 5e D&D?

I tagged both with general dungeons-and-dragons and dnd-5e because I want both his current status and where he came from.

Answer 1

Eilistraee, The Dark Maiden

In 5th Edition Material, we see precious little on Eilistraee. In the Sword Coast Adventurer's Guide, we see:

Some drow exiles have heard the song of Eilistraee, urging them out onto the surface to behold the moon as it rises. The drow goddess of song, beauty, swordwork, hunting, and moonlight, she is the patron of drow who reject the evils of their society, offering them light and hope.

In the AD&D book Demihuman Deities, Eilistraee is given more attention. Here we learn "the message of Eilistraee":

A rightful place awaits you in the Realms Above, in the Land of the Great Light. Come in peace, and live beneath the sun again, where trees and flowers grow.

Followers of the Dark Maiden also observe a festival meant to bring Drow and non-Drow elves together:

At least once a year, priests of Eilistraee undertake a Run. Those who are not drow blacken their bodies with natural dyes and oils. All priests, drow or not, boil certain leaves and berries to make their hair silvery, and go wandering (on the surface world). (Hostile drow say their silver hair indicates that the brains within the head are addled, though many drow who do not worship Eilistraee have silver hair.) Trusting to their music, kind ways, and sword skills to keep them from being slain as drow, priests of the Dark Maiden go where they are strangers, making an effort to seek out elven communities and bring them game, kindness, and helping hands. They try to learn new songs, music, and sword ways, and do not come to preach their faith or make a mark for themselves.

Answer 2

In the same books that describe Eilistraee, The Dark Maiden, as shown in the first answer, there is also her older twin brother

Vhaeraun

Chaotic Evil Drow deity.

Sword Coast Adventure Guide only drops a single sentence on him:

Selvetarm is god of warriors, and therefore patron of male drow, although perhaps not so much as Vhaeraun, the rogue god of thievery and of drow males who rebel against the matriarchy.

Demihuman Deities, on the other hand, describes him in greater detail, as a deity that wants to replace both Lolth and Corellon (his parents) on top of then-joined Elven-Drow pantheon.

Vhaeraun (Vay-RAWN) is the god of thievery and the furthering of drow aims, interests, and power in the Night Above, as the surface world is known to the faithful. He is also the god of drow males opposed to the matriarchy of Lolth, teaching that males are as skilled and valuable as females, and thus passively opposing the teachings of Lolth's priesthood on this point. He believes that drow should work with the other elven races for common advancement and never associate or trade with duergar, svirfneblin, or other dwarven and gnome races. (Humans and halflings can be tolerated.)

Dogma: The shadows of the Masked Lord must cast off the tyranny of the Spider Queen and forcibly reclaim their birthright and rightful place in the Night Above. The existing drow matri-rchies must be smashed, and the warring practices of twisted Lolth done away with so that the drow are welded into a united people, not a squabbling gaggle of rival Houses, clans, and aims. Vhaeraun will lead his followers into a society where the Ilythiiri once again reign supreme over the other, lesser races,and there is equality between males and females.

Most recent details on him and his siblings are in the Mordenkainen's Tome of Foes, but I do not have access to this book.