Boom!
The Mamba's tail hit nothing but empty air as it looked around in bewilderment, searching for Dara.
It even went as far as checking beneath its tail, to perhaps find a flattened Dara somewhere within the rubble.
Spurt!
It heard a sound of spurting blood, and the Mamba instinctively bolted towards that direction with another tail whip.
Dara had previously redirected all the qi being supplied by his 'Free Meditation' into his amour to become invisible, and then used the 'Ghost King Steps' to flee from his previous position.
Thus, by the time he appeared at his current position, the internal injuries caused by his clash with the Monkey suddenly relapsed, causing him to spur another mouthful of blood, which in turn gave up his position.