Killing Warlocks as a Knight:
The following strategy can be applied by Knights when hunting any creature that uses Magic Damage as its primary means of damage-dealing, but is especially useful against the Warlocks in the "lobby" of Demona, i.e. the area that leads to the three other rooms and contains a pentagrammatical formation of walls. Bring a Closed Trap with you and make your way to either the north-western or the north-eastern vertex of the pentagram without fighting any Warlocks just yet. Place the trap inside the one-way passage and lure a Warlock to your vertex of choice. Now quickly position yourself inside the vertex and diagonally adjacent to your trap, which you should open at this point. The Warlock will not know what to do – he can only reach you with his attacks from the square the trap is on, but that position also leaves him vulnerable to your strikes. He will therefore keep ambling back and forth between the trap square and the one before it without attacking you with any of his magical attacks. Attack the Warlock (but make sure Chase opponent is off!) and keep opening the trap over and over in order to prevent him from going invisible. When he is about to run due to massive blood loss, lure him into the vertex and trap him. He can attack you properly now (obviously), but the few remaining hit points he has left are easily eliminated with the help of some physical spells. Rinse and repeat this strategy with the other Warlocks in the room, and your days of burning your feet while frantically chasing after invisible Warlocks like a headless chicken are finally over.
Path:
In order to get there, you'll have to go through the MoLS. Refer to Route:Demona.