Does anyone know what is needed to unlock the green key master with liches? I've already done everything, only this remains.
For those interested, here's how I dealt with the knight who couldn't be caught in the dungeon. I lured him out with a level 6 unit during the Week of Equilibrium (which is important!) and defeated him with three low-tier units (1500 archers, 900 zombies, 340 ghosts), using sword walls and fists.
Everything is fine. You just need to visit everything that is on the map. In this case, you need to visit the altar to get the Weakness spell, and then the lich with the key master's tent will become available.