While Arod was evading his Ice Prison seishin spell, Prince Aragorn chanted, "Ye who represents purity, cleanse thy master's nemesis, swallow everyone in your master's way, Serpent Wave!"
Blue seishin essences started to gather around the elven prince when he started chanting the Serpent Wave seishin spell. Since Arod was evading the Ice Prison seishin spell, he was too busy to notice the converging blue seishin essences.
In the middle of his chant, the blue seishin essences that Prince Aragorn was able to transform the blue seishin essences that he was able to gather into vapors of water. At the end of his chant, these numerous vapors of water formed into a big wave in the shape of a serpent.
After Arod finished evading the spikes of ice from the Ice Prison seishin spell that the elven prince had launched toward him, he was surprised by what was launched toward him.
'Crap! That seishin spell was a diversion!' Arod could only think to himself.