The Puzzle with missing pieces... Part-2.

Staring at the setting sun, Idri continued in a solemn voice.

"In that strange underground building, I found a familiar type of altar on Floor 1, which is the lowest floor…"

"There are old records of the previous Dragon King finding various similar altars in that time when Mana first descended in this world…"

"The previous Dragon King speculated that those Altars all had a forbidden magic tainted with miasma and corruption hidden inside them… The previous dragon king destroyed all of those altars himself…"

"This prevented the forbidden magic from spreading into our world; if not for his that action, there would have been a lot of people in this world who would have mastered horrible and cruel magic forms by now…"

Forbidden magic mostly refers to those practices or spells that use life force, souls, and corruption as their power source.