The whale walked alone inside the castle and stopped at a distant spot within its interior. There, a corridor not fully visible awaited. According to Ruri, she and the others were able to spot this, as well as the last hidden corridor of the castle, thanks to their elevated cultivation.
That was why she had forced herself to break through realms, hastily rebuilding her body without resources. She tried to enter, hoping to find something useful. However, without complete mastery of the formation, they couldn't open any door; only the whale, who possessed the behemoth bloodline, had that power.
The castle had three hidden corridors, each protected by defense mechanisms to prevent theft. The level of defense varied according to the importance of what was stored inside. Forcing entry would trigger unprecedented destruction. The entire castle was the core of the city; if they did that, the city would collapse even if they could survive, so they didn't attempt anything like that.
