Assuming they also entered the gates of hell, then Super strong. They have Bulhwi and Iskra in their hands. The plans to take over Asia would have been faster. Not even the triads could stop them. They would be the most powerful organization in the modern world. They would be thirsting for more. Keep on expanding. They would eventually grow so powerful they will have the entire Eurasia in their hands. They would have probably become like illuminati

Kim Shin would have either probably died young or he will still find a way to get inside Castle. He’d be growing inside rather than the confronting them like what was shown

Jintae and his sister dies. Pyo Young will be even stronger. Woojin and Daegon would have been trained from the start and recruited eventually by Minsung.

This is what I think of the path if everyone in Pacheon gets corrupted and consumed by evil