These dragons where born from gemstones in the seawater of Toril, but traveled back to the The Spires of Darken Stars.
Their symbol is two triangles with an eye in the middle, very similar to Tora's their creator.
In Toril they are a symbol of Astral Sea and humans does not believe in such creatures to exist in the first place.
Only children can actually communicate with them just fine, they rarely but mostly seen in the first day star on the skies in the early morning.
They are peaceful creatures, they do no harm to people and mostly very shy, but dangerous when it comes to being on the open sea at night.

In the dark night like blue ocean of The Domain of Cobalt Might, where the elder Storm Tigerdragons lives.
rumors say that there's a small hollowed island somewhere in this vast ocean that their crystal is laying, they hold a prisoner so dangerous that it might destroy the reality to everyone known.

They love keeping treasures just like chromatic dragons, even so to the point they will defend it with all their might.
They only talk draconic and can easily manipulate other younger dragons to either worship them or die for their needs.

In the dark they become hard to detect, they are one with the dark waters as they stalk and predatory instincts to feed upon unfortunate souls of the ships in seas.
They come with various spells like:
Axiomatic Storm, Animate Water, Cloudburst, Dark Tide, Depthsurge, Drown, Mass
Dragon Cloud, Eye of the Hurricane, Favorable Wind
Algid Enhancement, Animate Snow, Boreal Wind, Cold Orb