Irregular

An Irregular is a being that has forcefully entered the Tower without being chosen. All the known Irregulars that have entered the Tower are famous for being extremely powerful, and have wreaked havoc and terror within the Tower. Their mysterious ability to control and manipulate Shinsoo exceptionally well is also deemed abnormal by the residents of the tower, as Irregulars are capable of having more freedom in controlling Shinsoo even with the restrictions imposed by the laws of the Tower. It is interesting to note that all known Irregulars that have become Rankers have surpassed every single active High Ranker in just one act, Phantaminum storming Zahard's palace, Enryu killing a Guardian, Urek Mazino fighting toe to toe with Arie Hon then being deemed stronger by the latter. It is also interesting to note that none of the known Irregulars have the same position, possibly hinting at the creation of an elite team that could reach the top of the Tower.

Zahard & 10 Familes
Although King Zahard and the 10 Great Warriors 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 (Wave Controller)
 * Phantaminum (Unknown)
 * Enryu (Spear Bearer)
 * Urek Mazino (Fisherman)

Trivia

 * Irregulars aren't all deemed lethally powerful. Such as Rachel. It is just her namesake.