In DotA Allstars, Luna was a night elf. This fact was ignored in Dota 2 due to copyright, as night elves are a race from the Warcraft universe.
The history, accent, Selemina phrases were borrowed from the culture of the Celts. In their history, warriors were often mentioned, who were mystically connected with the moon.
The name Selemine is most likely a reference to the Greek goddess of the moon and the night, Selene, and in Roman mythology, there was a goddess of the Moon, the patroness of the night.