well they rely on casting speed, and they are stationary when casting... which leaves them vunerable to meph/bosses. With orb and blizz u can cast and move around while the time delay wears off(dodging his attacks) whereas it takes alot longer to shoot meph with lightning. Besides... mephs lowest resistances is to cold, so its extra dmg there. Lightning sorcs are real good against weaker bosses thogh, like shenk, pindle, and eldrich. My lvl 81 orb/CL sorc owns all those nasty cold bosses with CL/Lightning, but orb works alot better on meph than a light skill.
Trying to kill mephisto with a pure Lightning sorc is a bad idea. I had one and she did great against anything else. THe damage range is just horrible if you try to kill Mephisto with Lightning or Chain LIghtning.
You can do it with CB, but i'd recommend taking a merc with you for tanking, unless you have max-res
Still it will take alot more time to kill Meph with a Lightning Sorc. Meteorb and Blizzard Sorcs are just way faster.
A lower resist wand might speed this up a little.
LOL, you all have no idea what you are talking about. Pure lightning sorc here and with above average gear, its 4 static fields + 6 lightning bolts to kill meph. Thats pretty fast imo. And how to get that gear? do the moat trick of course.
That said, you MUST get gear that reduces lightning resists. Besides lightning facets, the gear you must use are Crescent Moon Runeword, griffons eye, and 4 item tal set orb. The first 2 are also the most damaging lightning gear there is.
Crescent moon is quite cheap and quite effective (um rune and 3 socket blade), but you need fcr and resists from other places. All it provides is increasing your damage against mephisto by 140% and 0 resist mobs by 35%.
Get a phase blade crescent moon and watch people ask you what the hell you are doing with a lightsabre