Obtain a Kezathin's clipboard, hold and use it. These are bind-on-take, so you have to do the mini yourself or at least get to the area after Kezathin is dead to loot his corpse.
You need to obtain a teletrap from a Fey Diplomat in Vir (Diplomat Street).
Using the device will port you into The Annihilation Chamber in Unseelie. This Room is a timed death trap (5 seconds barely).
You can exit this room with a key from a covert operation agent in Cavhfail (uncommon loot).
You need to do the Keep access mini quest to reach the mob (search on the wiki for the mini).
Upon entering the Annihilation Chamber, search for a hidden northeast and unlock it with the key to get out before the timer.
For exhibiting uncharacteristic creativity and intelligence, the Powers granted thee a Mark. You have been granted The Mark of Creativity! You gain 250,000 experience points! You gain 53 practices!