"I sent you some friends..." Karyk responded. "Since I can't use them here, it's better if they accompany you."
Even though Karyk could still access that space whenever he wanted, but because he sent some Death Generals to Gabriel, he was connected to the same space as well.
That also allowed the two of them to keep in touch, without leaving any elemental trace.
As for the Death Generals that found Gabriel, they were the same that Karyk had sent to destroy all traces of his fake identity. The shadow couldn't return to him, since he was under the watch of the Four Generals. That left only Gabriel who could take care of them
Gabriel didn't stop walking, but he kept glancing at his shadow. Just recently, he was getting jealous that Karyk took everyone with him, but to his surprise, he got everything back, and even more.
In the Shadow Region, there wasn't only the Death Army of Gabriel. There were also Jia and the Goddess of Nature.