Naruto Chapter 550

[Tofu #2]

Why does a UCHIHA bloodline skill require the power of a SENJU to power it?

So Shisui could only use his own ability once every 10 years while he was alive?

According to the naruto wiki, danzou's right arm also belonged to shisui. How did he find Shisui's corpse when nobody else could?

[poopdeville]

Why does a UCHIHA bloodline skill require the power of a SENJU to power it?

So Shisui could only use his own ability once every 10 years while he was alive?

According to the naruto wiki, danzou's right arm also belonged to shisui. How did he find Shisui's corpse when nobody else could?

Shisui could use it any time he wanted, within "other" limits (e.g., running out of chakra). The Senju are distant cousins to the Uchiha, and have potent enough chakra to use the technique, IF they get their hands on the eye.

I don't know about the arm. Maybe Danzou used Shisui's ability on Itachi with his Hashirama cells.