KBD: Like it's been said many times the teleport right next to the cage should be removed if you ever want to see any pking in activity in here. Also like mentioned in OT theres 6 lesser demons in the cage, while in OSRS there is 4. To explain it to dummies; More aggroing npcs there is, the harder it is to keep aggro on the opponent.
Magic:
Don't think I even need to say anything here...
