The Ex-ranked Labyrinth was quite special because the respawn rate of monsters was very high. Ryan had to erect an illusion capable of hiding presences and had to maintain an invisible wall to keep them hidden. During this whole time, Umbra was the only one moving around killing monsters.
He made sure Umbra had the necessary nutrition during that time. Tia's blood was beneficial for Umbra even though it had been used once.
For a while, Ryan was worried that the boss monster would raid their hideout but fortunately, the Labyrinth was very huge. Umbra had reached the final point of the floor a long time ago but didn't walk past the gate.
This allowed them to keep hiding while building strength. One more thing that made Ryan worried was the fact that the time difference in the labyrinth was too large. This meant that his enemy also enjoyed the same privilege.
