Blue crystal

I finally completed your map. The final battle is intricate, but it’s fun and not too difficult. I played as the Necromancer – Lucretia. When I accumulated a critical mass of vampires (~40), I cleared the map using only them, even cutting down enemies without losses at the beginning. My build focused on darkness, light (I just wanted to buff my units), and I took Frost Nova for defense. It countered the creation of phantoms very well. I killed them all later (the last one was just a gnome with dragon elementals, which vampires can’t drain, so I had to develop summoning instead of light with 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. In the end, I defeated all the guardians without much difficulty. I easily defeated the Earth guardian against Banshees, skeletons, and zombies. The Air guardian against Ghosts, Vampires, and dragons also wasn’t a problem. Problems started with the Water guardian – I only had liches among my casters, so I split a hundred liches into 2 stacks of 50 and also passed it without much difficulty. I had to work hard against the Fire guardian because my remaining archers – the same liches – died from the initial fireball. I had to fight the Fire guardian with all my might. I lost again; his fireballs are too painful. I looked to see what could protect me... Reflection, magic resistance, undead protection from magic, and some other ability in chaos. Ah, and 50% fire resistance in light. Well, I had to go back to light; thanks for the mentor <3 In the end, I passed the Fire guardian this time, losing everyone except the vampires.
Overall: I liked 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!