Okay, Xanamech Nexmirthafen is an oddity, I tell you.
I will list the good points of him first.
1. Fire and Magic based resists. The spell says 'hit with steam' so I am going to say thats where the fire comes in.
2. NO FEAR! :o) However, a stun. Stun hits for 300'sh, and he has a Al'Kabor' type spell for roughly 800. Both are resistable.
3. Has roughly 150 - 200k HP's.
4. He is slowable, I believe. Occlusion him, Tash him, then Malo / slow him. Must be debuffed in that order or slow will not hit.
5. No dispell.
Bad points.
1. FAST! This guys is hasted at about 300%.
2. He does, in fact, quad 1390. However... it is a weird quad. It only happened one time. So, I am thinking that he has a CHANCE to double attack, and is usually only useing his two claws, giveing him duel weild. I studied the parse from from my log and poor Arduin took close to 3k in about, ohhhh, 4 attacks. Needless to say, he respawned at the zonein a while later. lol
3. Resists are not too bad other than magic, however Lure of Lightning did hit him for full damage + ID3. I believe LoLightning is magic based, can not remember.
4. We had a guild attempt him last night, however I did not hang around to see the results of thier raid. They had around 40'ish people with them, and they are one of the Big 3 on The Rathe, Noble Blade. Like I said, I don't know how they faired.
Nitram Anizok - The Gnome will argo to your raid if you are not careful. No Illusions for you! He don't like Imps, Werewolves, nor does he like Skellies. He will tolerate bears however. The Gnome is also exeptionally rough! He is one tough cookie! Hits for about 200 on average and is rather quick. He has I am guessing 50k'sh HP and in a pinch you could possibly let him tank for you. I do not know if he is charmable or mezable.... the raid said he was, but I could not confirm nor deny it. However, his resists are pretty wimpy. I rooted him several times just to give our raid a manabreak. He takes you to the right, and it seems as though you follow him for SEVERAL minutes, about a good 15 at least. Memblur is also a good thing on the gnome. Should he argo your party, simply memblur him and he will repath back to his original track.
His pathing is ALLLLLLLLL screwed up. We arrived at the junkyard to spawn the junkyard dog (see pic above) and I rooted him to regen lost mana, and get buffs right. Despite the propper steps, the dragon ripped us apart. We had him down to about 60 before we collapsed. Xenamech is not actually spawned when you arrive to the junkyard. He is there but untargettable. Layin like a junk pile. There are a few adds in the pile, but those can be pulled before you let the Gnome go tinker him.... which is advised. like I said, just root the gnome and pull the adds before you go in with the gnome.
I hope this info helps out anyone that wants to take him out. If a pickup raid is going to try this, make sure you have some experience on your side. About 50% of our raid was 60+. We had roughly 30 people. I would imagine 40 Ubers or 55 - 60 everydays could do this fairly easy. Its all about DPS, and MR (for the stun)/ FR (for the steam).
Good luck and well wishes!