It once belonged to Acilius Bolar, an Imperial Blade who survived the attack on Cloud Ruler Temple by the forces of the Thalmor. His blade, along with his written oath, were placed at the foot of the Shrine of Talos in Bloated Man's Grotto before he met his death at the hands of the Thalmor.
It strongly resembles the Akaviri Katana (Oblivion), the sword the Blades used during the Third Era. The hilt, (or tsuka), is wrapped in black leather, and the guard, (or tsuba), is a stylized coiled serpent.
- When equipped, some NPC's may say: "Be careful with that fire", even though Bolar's Oathblade does not have a Fire Damage enchantment.
- The content of the Writ may suggest that to protect the shrine, Bolar left to fight the Thalmor chasing him in the hopes that when he died, they would leave before searching the area, thus leaving the shrine to Talos unharmed.
- Ill Met By Moonlight it can be acquired by waiting at least a month in game time. This resets the grotto and the blade may be obtained.
If the sword hasn't been acquired before completing
- Possibility #1: Sinding has to be killed for this to happen. Revisiting the cave after more than a month in-game and Sinding is still standing around doing nothing and the shrine, where the sword should lie, is still destroyed.
- Possibility #2: Sinding doesn't have to be killed. Waiting more than a month and the blade was there, even though Sinding still lives.
- Possibility #3: Waiting one month in game time will reset the grotto, but both the oath and the sword may not lie where they are supposed to be, near the Shrine of Talos' feet. Instead the oath will lie in the rubble in front of the Talos statue where a chest can be found. Turn around after finding the note and you will be facing the table where the shrine of Talos stands upon. Look at the ground behind the table (between the statue and the table) and you will find the sword laying over there. This has been confirmed on PS3.
- The blade may stay equipped when in Werewolf form, forced or willfully activated. It can be sheathed or pulled out and used as well as the free hand to swing.