Gives a killtask for 50 Black Rats that are found near him. If you complete the task you get teleported past the floor puzzle in the dungeon.
By skipping the floor puzzle you will not get the xp and title that you would get if you did the puzzle.
Lore & Dialog
Ardenson tells you, "Generally people only come down here as a last resort or if they're too much of a brute to handle the task ahead of them. If you can prove your endurance by killing 50 of these rats I'll portal you directly to the next portion of the trials but I will think less of you."