The Rule of 3 Defining Jahad’s Era aka Then There Were 3 theory
Ever since Jahad locked the 135th floor and established his empire, his entire reign has been subtly governed by the number 3. His crest features three eyes, gives 3 orders, the rings that has his crest are total in 3 and his active rank sits at Nr 3.
Before Viole and Rachel entered the Tower to shatter the stagnation of Jahad's era, it was defined by neat, closed sets of three.
Jahad's 3 contracts: Jahad's absolute power and authority over the Tower are secured through 3 Guardian Contracts. Namely two are known as King Contract and Immortality Contract. I believe there is another unknown, hidden contract hinted (referenced in the exchange between Gustang and Traumerei after Administrator stripps Traumerei's contract), most likely to match UM as axis.
The 3 strongest Irregulars: After Jahad locked the door to the upper floors, exactly 3 Irregulars forced their way into the Tower during his rule. Unlike the 13 Great Warriors who grew up climbing the Tower, all three entered as absolute monsters from day one. Phantaminum, Urek Mazino, Enryu.
The 3 independent factions: Outside of the Great Warriors' direct control (Jahad's Empire & the 10 Great Families), there are only 3 major factions that operate independently or outside family association. Workshop, Wolhaiksong, FUG.
The 3 shinies: Obrion, Mago, Latur
The 3 Irregulars Without Immortality: Out of 14 irregulars who are confirmed to have climbed the tower, 3 didn't get the immortality. V rejected it. Hendolok was rejected although he got a different one and since UM never took the original climb with Guardian tests alongside the Great Warriors, he never had the opportunity, though given his nature, he likely would have rejected it anyway.
The 3 Active Top Towerborn Leaders: Based strictly on what is presented in the Webtoon which is canon, there are only 3 true Top Towerborns, meaning Eurasia Anne Jahad, despite being highly anticipated by fans to be a Top Towerborn, isn't one. These 3 Top Towerborns act as faction leaders and are each closely associated with a special Irregular something Anne doesn't fit in. Adori(associated with Jahad), Mirchea(associated with V), Baek(associate with UM).
Lastly the The Amizu Tragedy & The 3 Suicides: We know the reason why Amizu left Traumerei because she found out about Jahad and Traumerei. Later V was blamed for her murder. Interestingly 2 out of the 3 had died through suicide although V is alive, it's not his body anymore. Following the pattern started by the Amizu incident, Jahad who indirectly was involved will likely be the 3rd and final figure to meet his end via suicide/self-destruction rather than a simple defeat in combat.