So, if Ascendend are Sunborn...

"Sunborn" is a self-proclaimed title by the ascended.

What the sun creates, the moon can erase.

Followers of the sun worship the creations of the sun and probably wouldn't dare to question them. Followers of the moon acknowledge that not all creations are worthy of existence. Some are, some are not. It's like the sun is the reckless little brother who creates things for fun and the moon is the responsible big sister who picks up the mess afterwards.

I doubt the Iceborn are creations of the moon. If anything they could be followers of the moon. Lissandra's goal is to cover the world in ice... is she trying to erase it in the name of the moon? Whatever the case I doubt her actions would be deemed rightful by the moon.

But iceborn are all about ice, Ascended can shoot lightning, turn into animals, throw fire, eat souls, control sand, etc.

Iceborn = Void Sunborn = Shuriman, to an distant extend Targonian due to using Star power

Cold = Void Fire = Creation