Soften Stone Technique

Ishi Nanka no Jutsu (Soften Stone Technique)
Ninjutsu (Doton) [Earth]
Rank: 5 (C-Class);
Range: Close (10 ft. + 5 ft./2 extra chakra);
Effect: Turns up to one 1-cubic foot of stone into sand/round;
Duration: 1 round/2 extra chakra;
Saving Throws: None or Str negate (objects; see text);
Chakra Resistance: Yes (object);
Chakra Cost: 4.

This technique is the exact opposite to Chi Katame no Jutsu and turns 1 cubic foot of stone into sand per round; you may control what area the technique eats away at. No more than 1 such technique can be active at the same time by the user or a clone. If the targeted rock is from a man made object or mason, it gets a Str save with a +4 bonus to resist the transformation. The technique counts as though dealing 25 points of damage per round to a structure.