Blutsauger is a Treasure Tool in the form of a large broadsword with carvings on it. The carvings will light up blue when Power of Existence is channeled through it. Blutsauger's main purpose is simply as a melee weapon. However it has a special ability where, when the user channels Power of Existence through it, will cause the enemy to instantly acquire multiple cuts. The sword seems to have to meet physically to the opponent, such as a sword parry, in order for this effect to take place.
-- From Wikipedia
Replica of Mystes Yuji Sakai's "Blutsauger" sword (trans. "blood sucker") from the anime series Shakugan no Shana. 90cm. Carbon steel. Comes with a nylon sheath and backstrap.