User blog comment:MyProjectAlicization/Kuroyukihime - Kirito and Asuna's daughter?/@comment-221.181.34.204-20140110101931

And we also know that there are 2 commands that can affect the real body in brain burst, 'physical burst' and 'physical full burst'. kirito is the only one who thinks of these things,I think physical burst is made because of his incredible reaction speed and physical full burst is made due to the fact that he denied the system to defeat heathcliff