if i remember, using Mantra you can predict your enemie movement by reading his thoughts, and enel don't only read thoughts, he can also hear the sound clearly because of the vibration or something... so it make his mantra almost fail proof. : Luffy first idea was good, but since he couldn't attack with it, it was almost useless (almost, because he was able to dogde Enel attack)
Enel seems to be realy affraid.... i wonder if he dodge the Rifle attack from Luffy...


poor Enel.. hehe