Get the deathblow on Mr. Simes. He can make up to 12 attacks on the main tank and get in a full round of attacks on every formation member, so take extreme care. A form of 3, all with heal is the absolute minimum required to take him down. His room is CPK, and since he is a roaming NPC that means that wherever he roams inside the area, that room will be CPK.
Note: Can't have Mark of Fulfillment.