Throughout his long journey, Adam had fought dozens of powerful monsters and thousands of weaker ones. However, none of them possessed abilities like his.
Only recently did he realize that this was not surprising, because his abilities, like those of any Phantom, developed from the first monster he killed, or more precisely, from his Initial Gene. The Silver Weaver that Adam killed was the first of all the Silver Weavers.
Sure, any Initial Gene could be replaced or changed beyond recognition, but Adam wanted to preserve the essence of his powers, not wanting to completely abandon his origin as a Phantom.
True, if Adam had started his journey right now, he would most likely have encountered more monsters like himself, or even Phantoms with abilities similar to his.
But Adam had long since passed that stage. He was one of the first on this path and moved faster than most Phantoms overall.
Now, he had the opportunity to meet creatures like himself.