First, one had to concentrate the power of qi and blood on their index finger and draw the 雷 character on the palm of the other hand. Afterward, one would have to pour their mental energy into the drawn character and activate the power of qi and blood within it. And after shouting aloud ‘Lightning Palm’, lightning would appear in the middle of the palm!
Moreover, the 雷 character was quite easy to draw. It only consisted of thirteen not too difficult strokes.
It sounded quite simple, right?
However, if one wanted to use the Lightning Palm correctly… first, one needed a sufficient quantity of qi and blood in their body. Then, it was necessary to draw the thunder character on one’s hand and activate it with their mental energy.
Otherwise, one could forget about being able to use it!
雷 = Thunder/Lightning
Since people were discussing why cultivators weren't accepting westerns as disciples, here is the explanation. In CCG, westerns are more prone to become holy knights or mages~