Pioneer: I Can Open up Unlimited Secret Lands

[Black-hearted system + single-player exploration of secret realms + group exploration of ruins + old and cunning male protagonist] Chen Lu is an ordinary student who has not reached the standard of a quasi-warrior, but as a time traveler, he comes with the pioneer system. As long as he kills monsters and sacrifices spiritual objects in the secret realm, he can exchange for various rare items from the system to improve his combat effectiveness. Originally, all he had to do was grow up and stay alive, and one day he would become the top warrior. What he didn't expect was that as his strength increased, he would soon be involved in the vortex of the struggle between various forces, and gradually come into contact with more secrets. It turns out that the world of warriors is far more cruel than imagined, and the battle of life and death is a common occurrence. Moreover, many warriors have trained themselves into monsters that are neither human nor ghosts in order to become stronger. What is even more frightening is that there are even some ancient beings hidden behind a few top warriors...