Four Heavenly Kings

"With this, I will protect the innocent from any level of danger that it faces. No bloodshed shall be done within the protection of heaven itself!"

- Senkai when using the technique

is the pinnacle of Senjutsu and Barrier Ninjutsu used by Senkai, and was intended to protect those whom he holds dear, mainly being Konohagakure and it's people. The technique can only be wielded by those who have mastered the core teachings of Ninshū as well as attaining a higher connection with Nature.

Usage
Senkai first performs the Tiger handseal, followed by the prayer handseal, whereby four gigantic ethereal statues rise around a desired area, each facing one of the four cardinal points with Senkai as the epicentre. Each of these statues have their hands clasped; a symbol of prayer. The statues' hands separate and their palms face foward. Once that is done, a field is projected around the area which the statues are facing, which is noted to have the capabilities to be indestructable if the user's will is also indominable, as with Senkai's case. Due to the statues being outside the barrier confines, one would expect this to be a weakness with the technique. However, these statues are indestructable, and have dealt the heaviest of attacks without even suffering a scratch.

This technique bars even the usage of space and time from bypassing it, and can only be released by the user. Moreover, the technique only allows those whom have morality and virtue those carrying wretched evil within their hearts are rejected by the barrier, and have a gravitational pull that slowly sends them out of the barrier's confines. The statues themselves look into a person's soul, and are able to determine if one is straying from the path of good and remove them from the confines of the barrier. Due to it being constructed purely from the user's life force, vitality and the will to protect others through the shinobi sect, this technique does not have any chakra taxes, contrary to popular belief.

Drawbacks
Senkai must remain within the epicentre of the barrier for it's entire duration, and once it ends, the user experiences heavy fatigue.

Influence
In the, the are four gods, each of whom watches over one cardinal direction of the world, akin to the statues and the directions in which they face when the aforementioned technique is initiated. All four serve, the lord of the devas of. On the 8th, 14th and 15th days of each lunar month, the Four Heavenly Kings either send out messengers or go themselves to see how virtue and morality are faring in the world of men. This is another sentiment shared by the technique, in which it sees upon a person's good faith and virtue whilst removing those of evil hearts.