Ninja Arts: Double-Layered Method of Genjutsu

Ninpou: Kagemuku Genjutsu no Waza (Ninja Arts: Double-Layered Method of Genjutsu)
Genjutsu (Phantasm) [Mind-Affecting]
Rank: 8 (B-Class);
Range: Medium (20 ft. + 10 ft./2 extra chakra);
Target: One creature;
Duration: 1 round/2 extra chakra;
Saving Throws: Int negates;
Chakra Resistance: Yes;
Chakra Cost: 6.

This technique places an illusion upon a target who has already detected or who is under the influence of an illusion. This technique must be tied to an existing genjutsu effect (when the technique is performed). On a failed save, the subject will have the targeted genjutsu effect locked with kagemuku.

The kagemuku is a locking mechanism placed on the illusion, a second layer of sorts.
When a creature checks to dispel the targeted genjutsu effect, it checks to dispel
kagemuku instead. Up to 5 kagemuku can be applied to a single illusion, but each
kagemuku after the first increase the cost of the technique by 2 and decrease the dispel check DC of all kagemuku by 1 (the second application costs 8, the third 10, the fourth 12, and so on).

If the subject is not under the effect of the targeted genjutsu effect, the technique has no effect and the chakra is wasted.

Once per encounter, this technique can be used as an instant action immediately after
performing a Genjutsu technique.

Mastery
The second and fourth step of mastery allow this technique to be used an additional time per encounter as an instant action.