Enter Joko's Domain from the Bone Palace, get in a junundu, and head east to the quest marker where 6 Mad King's Guards will be waiting for you. After a short dialogue, groups of Awakened will spawn at three points and moving to your position; new groups will spawn as the previous groups are wiped out. For every foe killed, the Kill-O-Meter will increase by a small amount. The meter will also periodically decrease by a small amount, but you should have no trouble killing foes quickly enough to overcome this.