How do you use the Tsukumo talisman in Izuna Legend of the Unemployed Ninja?

You have to stick it in a weapon with at least 100 LUV and enough SP free to handle the Tsukumo talisman's SP. Then you have to Burn it in. That will Destroy the weapon (and anything stuck to it), and create a weapon spirit talisman (with same the amount of SP as the Tsukumo talisman you burned in).

For example: If you burned a Tsukumo (95 SP) into an Asura sWord with 100 LUV, for instance, you'd end up with a Spirit of Asura (95 SP) talisman, which could be stuck in, say, a Vampire claw that has at least 95 SP free, which would result in a claw that not only has the life-stealing properties of a Vampire claw, but also gives you higher experience gains like an Asura blade.