Similar to the Charlotte Vantage set, you could do something with the Sacrificial Knife, such as:
Shiro (Master Ninja) with
Vantage Vengeance Lifetaker
Certain Blow Death Blow
and Sacrificial Knife to get him into the Vantage-Zone. The Sacrificial Knife has an extreme base Mt, and if you want, you can switch to a Barb shuriken or a Soldier's Knife. I've seen this set in action before in a video, and can screw over even maxed out teams, although it is weak to Spy weapons.