1) Almost all creatures are very similar, the colors are dark, and as a result, I started to get confused about the tiers, alt-tiers, and the creatures in general.
2) Dracolichs don't fit the Castle at all. Well, only the name, because a dracolich is a dead dragon, an undead creature that has learned to use magic. But here it's just a creature, a ranged attacker that also applies buffs and debuffs of dark magic. And after looking at the "Stardust Dragon," I can suggest the name "Interstellar Darkness Dragon" for that dragon.
3) Gatekeepers are very slow and almost unplayable units, despite the teleports and other spells. Yes, Cave Lords were also slow, but they just sat there and guarded a single stack of ranged attackers, and here it turns out that levels 2.5 and 7 shoot, level 6 just stands still, and as a result, there's no one to go "tank." The very principle of gatekeepers needs to be revised; it makes sense to make them faster, give them something like a teleport (flight and animation of movement from point to point), and some kind of impact abilities.
Now about the advantages:
1) The idea of such a Castle is not new; as far as I remember, there was something similar before, but it was underdeveloped and raw, and here it is a well-thought-out and implemented Castle.
2) New abilities and new creature summons are also very good, although I haven't had time to test the elementals yet. As far as I understand, the mod will conflict with RTF precisely because of the elementals.
3) Having 3 ranged attackers against demons, while before there was only one, is also a plus.
And it should be noted that there is a feature: when recoloring lava, most modders forget to recolor one object, the lava rift; when viewed from a certain camera angle, it is covered in yellow from under the blue lava lakes. I don't know what it's called, but it's on the "War for Survival" map, on the red player's side, near the Castle
И пусть Эльрат осветит твой путь