Dreadhorn
In comparison to Dark Fathers, this guy is a push over. It is honestly harder to get the keys than it is to kill him. First you need to head to the swamp side, on the way pick up the two keys you will need that are laying on the ground, one is blighted cotton, the other I forget the name, but it looks like redish branches. Head your way to gnaw, hes in the cave at the end of the desert streach. He is a total wimp, paragon dire wolves are harder. Get as many keys as you want off of him. He is also a named, so has a chance to drop ML arties if you want to farm for a little while.
After gnaw comes the hard part, getting irks brain. Irk himself is not hard, nor is any changeling by themselves. Its Guile and the other named ones there. What I usually do since I have a second account with a stealth mage is have her stealth down to south of where you pout the keys in the statue and wait there. Honor past everything and join my mage. I just keep mage hidden, even if she times out, just there to res anyways. I head north and get all the keys needed one at a time. Its time consuming and I am reckless cause I know if I die, I have a res bot there. Another way would be honor and grab Irk killing his ass as many times as you can during honor. That works well if you have a 5 min honor going with Enemy of One. To max out honor, I suggest killing thrasher in Mels home. Give a tone of fame and karma and easy kills. Gnaw might be the same way, I dont know.
After you got your keys, turn them in and refresh everything you need, like pig irons, refresh pots, agility pots and str pots. I keep all of those on me. When you are ready to go in, honor yourself so you are not attacked, head in, enemy of one, honor dreadhorn, curse weapon and get ready to sit and chill for awhile once you attack, its a long fight. Follow my first posts rules on what abilities to use and your golden. He will knock your stamina down, so be prepared to chug. Never mind the poison obviously curse weapon heals through it.
If you can kill Dark Fathers, this guy is a punk.