Lava Release: Mount Vesuvius

Karasu will drain all of his chakra into his being, the chakra from the earth and heat, absorbed into his body, damaging him strongly, as this breaks his boundaries, but at the cost of this, comes a great power. Karasu will then augment the air and earth chakra natures absorb, turning all the areas that he drained from, into Lava. The ground, will become pools of Lava, reaching large radius. The heat from the air, is then also replaced by Lava, at this point, he will exert what left of his chakra. The cost being: Either Karasu's death, draining several years of his life, or near-death.