Ok, I HAD to write this (and I'll probably spam a little by posting it in two or three other spots because of importance.) I found an 'EASY' way to dodge lightning!
In the second main area, (after the travel agency) right when you start out - walk northwest until you come to the lake in this area. Where I stood was the corner of the lake (where you could either walk up-left diagonally on the d-pad to go towards the west side of the plains, or right/up-right on the d-pad to go towards the east and north ends of the plain respectively.) Lightning here dodges as follows: first bolt in about 8-10 seconds, followed by a 2-3 second interval 2nd bolt. It may sound a little odd at first, but once you get the timing down it is SO easy! I dodged, waited a few seconds and dodged again; ran back to the edge of the lake again and waited a few more seconds and repeated. Doing this, I was able to dodge 230 bolts in a little over 45 minutes (I think, I didn't time myself - but will next time) all this while STILL FIGHTING! I was able to capture all the fiends in the calm lands AND get the sigil very easily.
Secondly - I wanted to note this because in addition to the sigil, you also get a) 2x MP sphere for dodging 20, b) 3x Str. sphere for 50, c) 3x Hp sphere for dodging 100, and d) 4x Megalixer for 150. I'm currently working on a Tidus-only challenge, and those Str. spheres and Hp spheres will come in handy - especially early on in the game! Best of luck (you won't need it!)
