The Black Magician's Magic Pentagram

The Black Magician's Magic Pentagram is a Mu Lung + Nihal Desert quest started by Alcaster.

Part of Dr. De Lang, the Missing Alchemist: see every quest in order.

Requirements

Offer: Yes, Magatia is a town built right above the lab of the Black Magician. That's the truth, yet most residents of Magatia aren't even aware of it...
Yes I will... but before that, I want to clarify something first. As written on the note, did Dr. De Lang wind up conducting the experiment?
...Sigh. In that case, I have no choice but to give you some of the burden in regards to this event. The experiments conducted by Dr. De Lang were too risky and reckless, to say the least. He may have believed in the power of the Black Magician, but... the Magic Pentagram he made was made hundreds of years ago. It's probably already weakened considerably since then.
If Dr. De Lang's experiment is the cause for the epic explosion, then I am sure the Black Magician's Magic Pentagram is destroyed as well. The fact that the Magic Pentagram served as the foundation of Magatia, and if that's destroyed... you get the picture. I suspect that after Dr. De Lang's failure, Magatia itself might have been negatively affected. Isn't that so?
...I knew it. In that case... I may need to give you more responsibilities on this matter. Can you do something important for the town of Magatia? The town that is polluted with lies and deceit?
Completion: You managed to activate Black Magician's Magic Pentagram. Thank you so much for your help. I believe that with your great deed, Magatia will finally be back in peace. That said...