Houjutsu is a key power introduced in the 29th volume of GetBackers. It is the power to command and create logic.
Houjutsu is the power to control logic itself. At first glance, it may seem that one's techniques defy rational explanation, but in truth, it is the power of Houjutsu. As Himiko Kudo explained, not even Magic can escape the bonds of Logic.
Der Kaiser is the strongest user of Houjutsu in the GetBackers series.
The Logic of Infinity Fortress
The "Low" cannot stand against "High". This is the logic of the Infinity Fortress, and it seems that those who come from Babylon City utilize this form of logic. In other words, they can manipulate a higher form of logic in order to overcome the logic of everyone else.
Pretty much everyone that appears beyond Volume 30.