After seven days of traveling, we had finally left the place where the Trees of Desire were, one thing I noticed is that there were other monsters and plants with illusion abilities there.
In addition to protecting the mind against illusions by maintaining a strong will at all times, we should also keep fighting some monsters.
This wasn't a problem as I continued to use my intimidation skill to fend off the monsters by killing just one of each race that I asked Layla to keep and take to the Dungeon through my shadow.
It was a smooth trip for me, Nix wasn't affected by the illusion again, Layla tried to let herself be affected, but I told her to stop doing that since it was so bizarre the way she was smiling.
Orion was the only one who was never affected by the illusion, he just kept quiet most of the time if no one spoke to him directly.