User Echo Uchiha
A wretched transformation undergone through the power of the Onigan. This is a transformation technique that is activated when Echo gives up control of his astral spirit. Over one-thousand evil spirits possess his body, making his muscles expand excessively, giving him bulging black veins, and sickly green skin. Anyone under kage level who makes eye contact with this creature dies an instant death. This from of Echo rarely uses anything other than Taijutsu due to his godly speed and massive strength. For defense, the creature has massive waves of chakra constantly emitting from his body, similar in intensity to the flames of Amaterasu.
Even with such power, this form has a second transformation. After transforming, Echo grows horns and wings, and starts using even more wicked Ninjutsu.
In a final transformation, Echo becomes titan sized, so much that his upper torso is shrouded in dark clouds, and he can use virtually any technique pertaining to the underworld, even bending the reality of life and death.