Blue crystal

I finally completed your map. The final battle was a bit complex, but it was fun and not too difficult. I played as a Necromancer – Lucretia. When I had a critical mass of vampires (~40), I cleared the map using only them, even cutting down enemies without any losses at the beginning. My build focused on darkness, light (I just wanted to buff my units), and I took “Freezing Wind” for defense. It was very effective against creating phantoms. I killed them all later (the last one was just a gnome with elemental dragons, which vampires can’t drain, so I had to develop summoning instead of light at the mentor). This took about 5 months; the rest of the time, I scouted the map and completed the first and last quests, which involved passing through a wall. Towards the end, I defeated all the guardians without much difficulty. The earth guardian against Banshees, skeletons, and zombies was easily defeated. The air guardian against ghosts, vampires, and dragons also wasn’t a problem. I started having problems with the water guardian – I only had liches among my casters, so I split a hundred liches into two stacks of 50 and also passed it without much difficulty. I had to work hard against the fire guardian because my remaining ranged units – the liches – died from the initial fireball. I had to fight the fire guardian with all my might. I lost again; his fireballs were too painful. I looked to see what could protect me… Reflection, magic resistance, undead protection from magic, and some other skill in chaos. Oh, and 50% fire resistance in light. Well, I had to go back to light; thanks for the mentor <3 In the end, I defeated the fire guardian this time, losing everyone except the vampires.
Overall: I enjoyed it. Because I lowered the difficulty to normal, the difficulty really became normal. As it should be. I also like your approach – you can play as anyone, for anyone. This is valuable and gives the map replayability. I hope the green or yellow crystal is already in development!