Can you give me some info? It said it was forged by the dwemer but then why is it deadric styled and a deadric artifact when the dwemer scorned the deadra.

http://www.uesp.net/wiki/Lore:Volendrung

Basically, it is unknown how it became associated with Malacath.

I assume he wanted the powerful weapon for himself, so he took it and twisted it to his own liking to spite the Dwemer.