Nimjhal was half Bloodscalp. His mother (who was this viciously obese Bloodscalp trade queen) murdered his father (who was a darkspear warrior) for reasons I cannot recall. I always likened it to how insect females sometimes devour their mates, because she just seems like some kind of cold-hearted spider to me. Anyways, she trained Nim to be a killer, forcing him to go out into Stranglethorn by night and kill whoever he came in contact with. If anyone saw him before he took them out, she'd cut off one of his fingers as a reminder of his failure.
They'd regenerate, cause, you know, he's a troll, but it would still suck.
At some point in time, Nimjhal fell in with Degmarlee, famous in his own right as a trollish freedom fighter. They became good friends. I met Nimjhal for the first time when the defense call went out for Sen'Jin village. I arrived on scene to see three or four Alliance guys ravaging my town, so I went nuts on them. Just when I was about to go down, Nim appears and just totally takes the focus off of me. Long enough for me to get a few well needed heals in, at any rate.
Nimjhal and I became good friends, and I also met Degmarlee around that same time, though independantly of Nim. We were members of the Brotherhood of Dusk, but we weren't knights in the service of the Dark Lady or anything like that. I'm not sure we actually had an RP reason to join them, except, you know, they were an RP guild and we were RP'rs <shrug>.
At any rate, if you've not read that whole "A Letter on Tarquin's Pillow" thread, that has a lot of information on all three of us. I think the stuff I did was poorly written, both because I hadn't done much writing at that point and because I wasn't wholly familiar with Matsu's character at the time -- I'd really like to go back and redo everything I wrote in my new style, it could be much better.
I'll give you the short version of it, anyways --
There's fighting at Southshore and Tarren Mill, Degmarlee and Tarquin call a cease fire, and when Degs leads the Horde off the field for the night, the Alliance jack them from behind.
Tarquin earns the name "Oathbreaker" and a poisoned letter on his bed.
His then girlfriend (now wife) Ceil intercepts the letter and falls victim to the wrath of purgatory dust.
Tarq tries desperately to find a cure, kidnapping Shida, Matsu's younger half-brother in an attempt to coax a cure out of Degs.
Mats puts a curse on Tarquin. He made Mats' loved ones suffer, so in turn, Tarq's loved ones will suffer.
Tarq has a bout with remorse and decides to let Shida go, Ceil gets angry and tries to stop them.
Nimjhal ambushes Ceil and tusks out her eye.
And, yeah. I'm just trying to give a brief plot summary, you know?
Nimjhal was eventually defeated by Tarquin at Absolution in the Plaguelands. He was killed once and then the scourge virus got into his system and he rose again briefly in one of those classic horror movie scenes. He was flug into a fire pit and held there by Ceil's entangling roots.
I'd give you more, but I only woke up like 2 and a half seconds ago. :S