Just tried a lightning javazon as first character in the new ladder season. Currently lvl **, 20 in cs, lf, ls and 17 in valk. All prerequisites + 1 point in bow upto strafe (was gonna do a hybrid but my damage with a bow is so insanely crap compared to lightning i don't bother using one, or maybe i just need a better bow/equip). Putting the rest of my points in pierce since it's supposed to help vs bigger, tight groups (like cows).
These are my findings on companions:
Mercs: With a good weapon very useful in taking out lightning immunes (LI), don't count on him to tank though. I have a perfect upped shaftshop on him and he still dies in a few seconds sometimes (well so does the valk but not as much).
Take an act2 merc. Although you don't really need the auras, holy freeze is always a nice thing to have, or might in case you encounter lots of LI monsters and want your merc to kill faster.
Give this guy an insight (the highest rune is sol... cheap!), even in a crappy 4 socket scythe it's good enough for normal/nightmare (or infinity if u have the high runes). The meditation from insight gives you the opportunity to just totally forget about mana / regen / leech and concentrate on MF or something else more.
If you're lucky and find an ethereal elite polearm (i think cryptic axes are the best) with 4 sockets, with insight and might aura your merc can easily do 1800-4500 damage (well mine does). Since he does jab attacks that's more or less x3 as well i think. Either way it kills most LI, even bosses in a few hits.
Valk: great tank most of the time. Saves you the entire run/hit/run/hit repeat crap. You can just stand there throwing whatever you want while your valk keeps them busy. Just don't expect them to kill anything in hell in less than 20 seconds (even at lvl 17).
Decoy: Useful sometimes, especially in hell when you are, for example, in worldstone keep and don't wanna break your neck trying to find out if there are 20 gloams/black souls ahead. Also good for breaking enemy groups up, by casting one behind the group that is rushing towards you, half of them will stop to attack the decoy. I didn't put more than 1 point in it,
Merc / Valk is a great combination, but alone a merc will be rather useless since he'll die too fast, and a valk alone will give the monsters something to chew on however will not help much in taking out LI.
I can not understand why people don't use mercs or a valk (even just put 1 point in it). It's like getting 2 free party members without increasing monster difficulty.
@Valironean: you said you don't need a merc for the pit or cows. I can understand the cow thing; the only LI there are bosses.
But can you please tell me how you cope with the LI archers in the pit without a merc? The only thing i can think of is that you jab or whatever other skill that doesnt use lightning... which would all be rather low since you'd have spent all your points in lf, cs and/or ls. It's possible but not much point since a decent merc will do about 3-10 times as much non-lightning damage as you do...
