Ancient Cathorni worshipped a being known as Vlonthel who has similar domains to Unre, is depicted as a drow, and is armored and equipped like Ava (when Ava is depicted in humanoid form).
An ancient myth tells of Vlonthel slaying 6 dragons, each with a different weapon. The following details have been discovered:
Mozikth the Blue was slain by her spear,
Norixius the Green was slain by an arrow,
Quespa the Copper was slain by her spear,
Drethzeimfaaz the Cobalt was slain by a spell,
Nuthraiann the Black was slain by her war pick.
It seems that one dragon is missing from the lore uncovered by adventurers thus far.