The Ultra-Limit System of All Realms

This is a newbie writing a book, so please forgive me for any mistakes. The protagonist Xiao Chen was reborn in the ancient world and also obtained the system. This system will help the host to travel through thousands of realms, and each realm has an extreme realm given by the system, and the host must defeat the peerless evildoer and protagonist of all realms (with the same cultivation level) at the extreme realm of each realm in order to advance to the next realm.