Irregular

An Irregular is a being that has entered the Tower without granted permission of Headon. Irregulars are all famous for being extremely powerful and have wreaked havoc and terror within the Tower. They also seem to have a strange talent for using Shinsoo

Zahard & 10 Familes
Although King Zahard and his men came into the Tower from the outside world in ancient times, this was before the testing system was invented. They are not considered as Irregulars because of this.

Known Irregulars
Baam

Lahel

Phantaminum

Enryu

Urek Mazino