Use Fatlegs catapult (Xavapult) in the Towne of Xaventry to land in the room On the Branches of the Sinwillow Tree quickly find the down in the center of the 3 x 3 and head inside to visit the raised houngon.
Path to take is d;d;d;nw;nw you need to be invis to pass the mobs and you need either a Huruk's Soul or an iron-plated solenoid to not be kicked out and recieve the mark.
Note: The branches will drop you into normal Rune Forest randomly so you need to be quick.
For becoming an associate of the raised houngon, the Powers have granted thee a Mark. You have been granted The Mark of Deterioration! You gain 65 practices!