Traveling Back in Time and Acting as a Villain to Make the Protagonists Fight Each Other

The big villain in the Dragon King novel who traveled through time, but discovered that this world is a fusion world. As a big villain with a system, he started his burning operation and instigated the protagonists to fight each other. The urban protagonist likes to unify the underground forces. Secretly supporting the underground forces in one novel world and attacking the underground forces in another novel world. Let the protagonists kill each other This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.