I feel like you just described an NPC, not a PC class, really.
I disagree, not every PC has to be Good, I find evil for a good cause to be a perfectly valid, this PC believes murdering and torturing a Drow leader in the Drows own city, to intimidate them into leaving the Elf Gloom Stalkers Even homeland and it's loved ones alone. I can ironically see both a lot of Gloom Stalkers among underdark races, and among the followers of Sheverash, the Elven God of Vengeance, most specifically against Drow who the God hates with a disturbing intensity.