In a vanilla, untouched game? Not so much. Closest would be stealth archer or mage. Though, they don't kill anyone near her, per se. The other way around, actually. Keep opponents away or you'll find yourself getting bent over in short order. Though those two builds definitely excel when it comes to handling things at range.
Now, succubus build Lona is less about making war and more about making love, but the end result is probably what you're looking for; get the jump on anyone and just fuck them to death. a bit of investment and you can tear through Goblin/Orkind lairs with ease. Just be sure your holes don't get too lose or you'll be doing scratch damage in sex battles.
If I were you, I'd just go through the game files in the Data/Effects folder and modify things (stamina costs, weapon damage, etc) however you wish. This game seems fit to screw you over at every turn unless you use very specific builds. So feel free to make things a bit more fair.
Or you can just use cheats, I guess. Bit of a nuclear option, but we don't judge.