okay, sorry i'm late but i had a crap day yesterday and didn't really want to put any of that into this. on that note.....
sorry if this sounds rude but what idiot would hold something as heavy as lith would be parallel to the ground with one arm without holding it at it's center of balance? that would put excess strain on his arm and leave him vulnerable to the types of attack he's expecting. the best positioning for what he has would be;
kneeling down with lith in his right arm, using lith's guard to protect his arm, the head on the ground in on his left and in front of him. holding geth in his right, armored arm to protect his right. like this he can move lith to defend most of his body from above, the left and the front with minor protection on his right which is supplemented by his right arm. but due to me not thinking clearly when posting i didn't include all that and at any rate lith would be placed with the tip in the ground to reduce strain on the fighter.
second, while size wise lith isn't that large the surface area of it is roughly twice what it appears due to the 'petal' blades (which i keep calling petals due to each being about the same size as a standard rose petal) that cover the entire surface and overlap, also counting the small gaps between the rings that allow them to spin. giving the entire thing as a whole a very large surface area.
this one i have to call into question. looking at your sheet you only mention that he discharges the electricity, not that he can control the path it takes meaning that really his attacks shouldn't be able to arc in the manner you mentioned. with how you put his ability it can only be interpenetrated as he can launch bolts of electricity but he can only fire it in a direct path. meaning that while it doesn't follow a straight line is you were to you could draw a straight line through the path it took like a graph. you made no mention of being able to control electricity, only generate it, so really as soon as it has left your body it would be nothing more than an aimed lightning bolt and therefor unable to pull off the precise hit you're saying he's using.
another note about his lightning, both his ability to charge it fully while still fighting normally, and it's base power that you stated is "capable of outright killing a human, leaving burn marks and smoke rising from their remains" mixed with your fighters ability to use it as an essentially unblockable/undodgable attack comes across as op in my opinion. as seen when you one hit killed the only opponent you actually killed. your charge has little to no effect on your character where a normal charge attack has some kind of drawback while it is charging, despite this you have displayed him being able to use even advanced moves such as the sword without and drawback while charging your bolt. the only noted drawback being that he can't use the hand he's charging with which can be avoided since he doesn't have to use a hand to charge.
this one is covered in the first bit, since he knew he was against an electric enemy he covered as much as he could, expecting an attack coming from just his opponents general direction.
and sorry for this one, but it's my interpretation of the power you're using. with that said the power you've described comes across as something that you're not going to let me come away from alive if i do take any of the damage from it. after all this was the description you used for an attack against another character, that has less charge than this one.
" A white-hot bolt of lightning thundered from his palm straight at the grenadier's face, potent enough to burn a hole clean through a modern tank, along with setting the entire crew ablaze from sheer electrical current. The sound and light alone were twice that of a flash-bang grenade"
with that kind of power and you saying that i should be taking more than a little of the force. when, with the kind of power you've described 'a little' damage would be the loss of the arm holding lith and severe internal scaring and damage leaving my fighter crippled and basically dead.
all it sounds like you're arguing is that i take the drawn out version of you saying 'nope you're dead cos i fired in your general direction'