When Li Yang stepped into the beach, even he who was still at Qi Condensation, recognized that sudden warping of the island's air and qi.
It wasn't obvious to the naked eye, but he had felt the numerous formations available in the sand and even saw what appeared to be ritualistic totem-like structures. This was what accounted for him not seeing anything while they were still aboard on the ship.
The System didn't even need to signal him about it.
[ Island of Illusions ]
A hidden island dedicated to the art of training ordinary mortals to stage one to stage two cultivators. It contains a space suitable for those who wish to train themselves against illusionary enemies as well as the available monster beasts cultivated in the island.
This was originally created by the fallen cultivator, Liu Qing Shan.