Altar of the Wisdom King

Altar of the Wisdom King (明王の壇) is a most likely non-existent spiritual item made up by Tsuchimikado Motoharu in order to preoccupy Kamijou Touma long enough for him to go in his quest for vengeance against the "killing" of Tsuchimikado Maika.

Principles
The Altar is a special type of altar, an item used by  for mental training. Normally, a Homa altar is used to alter the user’s mind. The altar cleanses worldly thoughts to increase one’s focus, so they are not all that dangerous. However, the Altar of the Wisdom King takes advantage of that ability. Instead of acting outwardly, it acts inwardly. It is a special altar created to alter the minds of others. Once it is used, it will suck out all of the knowledge and skills of everyone within 5 kilometers. Not only that, the act of sucking that knowledge and skill destroys, apparently similar to the destruction of synapses and automatic nerves.

Agitate Halation Arc
Motoharu first mentions the item alongside that of Umezaki Yuuga, the magician who intends to use it, after he delivers a knocked out Touma in a locker room in School Garden inside a container. Touma then spends the entirety of the first chapter of the volume on a wild goose chase with the help of Shokuhou Misaki controlling a student. He promptly abandons the search after arriving at the most likely location where the supposed magician and Altar of the Wisdom King should be, as well as the fact that he discovers news of the "death" of Tsuchimikado Maika.