L'adovec

L'adovec is the prime deity of the Ice Flats and northern wild lands. He is primarily worshiped by the native Frostborne people, the drow, and the roaming clans of dragonborn. Little is known about his worship or followers outside of these cultures, and many followers of Xythys openly revile his worship and following, claiming it to be worshiping the cold embrace of death, brutality, and abandoning children to fight for themselves.
Nothing could be further from the truth.
Those who follow him are few and far between, but they know his teachings to focus on strength and respect. The 'worship of ice and death' they are commonly accused of, is more of a lesson taught early on to not fear what you don't know, to not fear what could kill you. It is better to understand and respect it, to know your limits and how to survive in harsh lands. There will always be strife and difficulty, but unlike the followers of Xythys, L'adovec claims that it is better to have the strength and wisdom to know how to survive a storm and protect what is yours, rather than hunkering down and praying that it passes you by.
In the murals and art within these temples he is depicted as a magnificent dragon, though depictions of his visage and likeness are based within the blessing that he gives some of his followers.
There are no active churches, but various temples as landmarks in the wild lands. There are no priests or religious leadership outside of L'adovec's Chosen, individuals who have undergone the trials to prove themselves worthy of upholding the ideals of strength and wisdom. Individuals who are able to lead others and help guide them. They do not expect strength from everyone, but rather from those who are able. There are several smaller tests of strength for those who aspire to it to prove their worthiness and adherence to his teachings, often focused on resourcefulness and preservation. The belief is that once individuals have proven themselves in these trials, they are reliable enough to be leaders, either spiritual or otherwise, and can be relied upon in turn. It's not a requirement for every person to go through with them, unlike what the hearsay would have most believe.
The Chosen are very few and far between, legendary heroes who's appearance is forever altered in the visage of their god, often bearing draconic faces, scales, thick tails, and horns. Even non-dragonborn bear some semblance of this form, with the scales and ridged plates the frostborne bear, with the drow being the primary exception to this. Their deeds captured in legend, often passed down in oral histories between the clans and tribes who worship him, but there are rare scrolls depicting their deeds scattered in the rare temples that serve as landmarks for the nomadic cultures. His worship has remained largely unchanged since the Shattering, since his followers are few, and remain within the more reclusive cultures of the world. It's not impossible to find believers in Ezeth as it is currently, but to find any sign is rare, and often kept under guard lest the more zealous followers of other gods catch wind of heresy.