Works the same as double accel, but at twice the rate. Drains more chakra from the user than at Accel’s previous stage. A Chuunin Rank/Skill-Level Shinobi can use this for four seconds per use of the technique, each additional rank adds 2 seconds.
Negative Side effects: Overuse (Maintaining the technique for more than 1/2 posts) will cause muscle tearing > oxygen deprivation > chakra deprivation > intense pains in the chest area, and eventually a hard attack. If fighting off the heart attack for too long it strikes with such intensity that it spells instant death for the user