Kai is from the Section of Motion.
The Section of Motion is extremely important, they are responsible for delivering cargo to all the sections. Supplies, weaponary, even anomalies are transported via them.
If they don't deliver food people starve, if anomalies are misshandle people die. if artifacts or weapons fall into the wrong hands the world become chaos.
Therefore, this is one of the sections that only the most prestiege are put in it. So you can assume Kai had to pull some strings to get there.
Kai is responsible for keeping cargo safe. Many different factions try to steal it for one reason or the other. It's Kai's responsability to make sure that doesn't happen.
Kai HAS to give his life to protect that cargo, a single artifact could bring the destruction of the whole world. And besides, a single life doesn't matter much if it means keeping an artifact like that safe right?