Phew, finally killed the pink "Legions of Pain." I started by clearing the area around my Castle and went downwards, collecting everything I could along the way. I killed the pink hero who came towards me with minor losses, then went downwards and captured the settlement with the crazies and the Castle located below. Then I went left (towards the pink one). He has two Castles, one below and one above. First, I captured the lower Castle, and then the upper one. At the same time, I was building teleporters in my Castles because the orange creature kept visiting me quite often, and I had to move from one Castle to another. He managed to recapture one of the Castles I had captured. Overall, I'm very glad I got rid of the pink one. He has a teleporter on his territory, right next to the upper-left Castle, and he will use it to recapture the lower Castle. That's it. I'll go try to drive the orange one away now.