The Knight Trial Secret Realm, or the "Everlasting Abyss" Secret Realm under the Rust Knight, has its greatest uniqueness in its "trial" characteristic.
Although the domain still focuses on combat, professionals can feel the rare "friendliness" within the Secret Realm.
You can quit at any time, fights don't necessarily end in life or death, and the attack patterns of magic monsters are quite suitable for "trials"... Assault-type Animated Armors, Shadow-assassin's Ghost-creatures, Stone-statue Ghosts and Minotaurs in chaotic battles can greatly enhance the practical experience of the trial participants.
The rewards it offers are also considered fair, especially for low-level professionals.
For ordinary professionals, most Secret Realms don't have rewards, just some extra "pollution" after leaving.
Considering all this, the Knight's Secret Realm is simply a great and friendly environment for freshmen, which has contributed to its popularity.
