Dawnfang/Duskfang

Dawnfang/Duskfang is an enchanted sword that is gained by completing the quest Baiting the Trap from The Elder Scrolls IV: Shivering Isles expansion.

It is unique in that the sword switches between two separate forms. From 6:00am to 6:00pm, it takes the form of Dawnfang, which has a red jewel in the hilt and does fire damage. From 6:00pm to 6:00am, it takes the form of Duskfang, which has a blue jewel in the hilt and does frost damage.

In either form the sword possesses the Nourish Blade ability. With this ability, if Dawnfang/Duskfang should end the lives of twelve beings before its next transformation, then when it transforms it will become a much stronger version of what it would normally transform into. For example, if twelve beings are killed by Dawnfang, then when it next transforms it will become Duskfang Superior.

The sword seems to possess sentience, as Grommok details in his journal that when he killed with it, he heard a voice in his head saying it has killed.