Headmaster

To summon this mini boss you will need to be doing the Eingren Manor quest.

Drop a Crystal Ball onto the Table at (8,9) to spawn a Crystal Ball.
The Crystal Ball will attempt to cast ard cradh, shock, ao sith, and poison spells.
It has elemental defense so curse, fas and use dark attacks.

After killing the Crystal Ball the Headmaster will spawn.
The Headmaster will attempt to cast ard cradh, ao sith, poison and Skull Splitter spells.
It also has elemental defense so curse, fas and use dark attacks.

Boss Tactics

Headmaster