Symphony of Blades

The Symphony of Blades is the final boss of the Depths of Malatar. It is King Narilmor transformed into an avatar of Meridia's power, in the image of an Auroran suit of armor with four arms and blades. In Veteran mode, burning the Dictates of the Lady of Light will trigger hard mode, where it will now summon colored dark orbs.

Source: uesp.net.