Eternity Trapped in Ice

Hyoukenseisou (Eternity Trapped in Ice)
Ninjutsu (Hyouton) [Cold, Shiseiten no Akira Hijutsu]
Rank: 10 (S-Class);
Range: Close (10 ft. + 5 ft./2 extra chakra spent);
Area: 20-ft. cube;
Duration: until destroyed (see text);
Saving Throws: None or Dex half (see text);
Chakra Resistance: Yes;
Chakra Cost: 13.

Using this technique, the user causes spikes of ice to rise from the ground and trap creatures in a 20-ft. cube. Creatures standing directly outside the area suffer 100 points of damage, half of which is cold and the other half piercing, which can be halved with a Dex save (DC 15). Creatures trapped within the prison suffer 25 points of cold damage every minute until they are freed or free themselves. Protection against cold, such as very warm clothes or Unki Tate no Jutsu will prevent that effect.

The prison is made of many, many ice pillars, 40 of which are accessible to the trapped creatures. Each pillar has 5 hit points, and will reflect the image of the user. The pillars have a fire, electricity and wind resistance 15, are immune to cold and water damage and will reflect back rays and thrown weapon to their origin. Any creatures within 10 feet of the pillars when a cone or line attack is used against them will also be affected, though the width of the reflection is the same as that of the attack's maximum.

Once destroyed by a melee attack, the pillars reflect back 10 points of cold damage to the attacker. Once 15 or more pillars in an angle or wall have been destroyed, the prison will be destroyed.

If attacked from the outside, 40 pillars are also accessible to the attackers, and the same method and penalties are suffered when attacking them (see above). If the user dies or falls unconscious, the prison is destroyed.