The Aqua Barrier Psych will activate once the stylus is trained on Neku for a little while. A blue ring will form around Neku for as long as the stylus is pressed, causing rapid health regeneration and temporary invulnerability; but also disabling movement. Note that Aqua Barrier is one of the few psychs that give health regeneration while having a reboot time, while too slow for serious attacks, this makes it very useful in long chain battles. It takes a second to start working, in which it may be interrupted. It is suggested you move away from Noise before using this.