Tsuiwonasu

The tsuiwonasu sealing method allows a sensei to permanently seal a chakra clone into himself. The clone is then able to act autonomously indefinitely. The clone remains sealed within the user throughout life perpetually regenerating its own chakra. In this way it is superior to the technique used by Minato Namikaze.

Methodology
A ketsuin (blood seal) is inscribed on the retina of each eye using the Kyrgyzishi's rhythm element techniques. This is usually done at birth during the installation of other seals, but can be done at anytime. Once inscribed the seal remains permanent. Upon death the seal vanishes as the twin's chakra dissipates.

Usage
This technique has multiple uses: breaking genjutsu, swapping bodily control with the original, providing chakra storage, performing jutsu, etc. The twin is an exact copy of the original user and has total access to the originals chakra network. Therefore the twin remains totally aware of anything experienced by the original.

Regardless of the attack the twin remains shielded from external chakra sources. Invasive techniques such as the Sharingan cannot penetrate these types of seals, as there is no natural connection unlike that of sealed bijuu and extra sealing precautions further isolate the twin's partition.