Earth Release: Burial Prison

Keeping up with Koshiro's deathly theme, he slams his palms against earth and shapes a casket which rises directly behind an opponent. When standing, he can push an opponent into said casket or create it around his target so it closes them inside. While on the ground, Koshiro can create a casket under, eliminating extra work of moving. The Casket has a wooden texture yet is durable enough to withstand fire release techniques. It can have a seal which forbids opening through an evil shock. Once trapped inside, Koshiro can use it as a prison or to reverse summon his new experiments to a lab. Due to it's durability, Koshiro can use his caskets for defense as well.

By kneading his chakra within earth directly under his caskets, Koshiro's enemies will begin to rapidly sink underground. The distance under ranges. However, it literally buries his targets alive, suffocating them until they die. He can use it for torture or to kill. The number also varies upon how many he wishes to kill.