Unit critiques:
Shadow Beast: sounds very interesting, but I think it might be better as a shadow spell where you sacrifice an animal to get the beast (perhaps kinda like how you sacrifice a warrior to get a drown (or in my version, any melee unit to get a drown with strength based on the units strength, but at higher costs based on the strength/level). I would prefer one type of beast per animal to be sacrificed (it could just be done with a new promotion that changes the stats/graphics, but I would prefer a new unit with stats based on the original animals (perhaps the same +1 shadow affinity) so it would be beast class and have more available promotions (I don't like the only gains combat promotions part) ).
Phoenix: I'm not quite sure that the Phoenix should be a Malakim unit, or that you should be allowed to have 3 of them (6 immortal units is a bit much). Also, I don't think its immortality should be limited to desert tiles, and it should obviously have the Flying promotion instead of just moving impassible . I would really prefer the Phoenix to be a late game hero, available to anyone with Divine Essence and Fire/Life mana (although still very expensive). It would be really nice if it could also cast Pillar of Fire. It should be based on Fiacra the Northwind model from AoI, but be aflame.
Drifting Echoes/Souls: I seriously doubt that this idea is possible.
The Fortune Teller: a nice flavor unit, but I would prefer to have one that actually changes gameplay instead of just adding another source of amusement when you're getting bored (if it were implemented, it would
need to have that pointless "tell fortune" spell, and the taro card throwing would be a nice touch).
Imager: I'm not a fan, especially since it is too close to to the Svartalfar conjurer UU, the Illusionist (whose summons with the illusion promotion). However, the ability to create illusions of the types of units that would compose your main army does sound nice. I would propose a shadow spell "Create Decoys" that creates illusion-summons of whatever types of units the recruit ability would have actually created.
Wonder critiques:
Elite school: needs a better name, and I don't think it would be possible to implement anyway. If it is, then it is a great idea.
Event Critiques:
The dark bosquet: What good would vampirism be to a Treant? They cant gain any promotions anyway, and I doubt the barbs would have a bloodpet on the same tile for it to use feed. It would just be getting a slight strength boost, and a weakness to Sun spells.
The Underworld Portal: this i way to long and complicated for me to bother to even read it
Mana Fluctuations: I like (except I'm not a fan of the double negative in choice B. In general, the wording could be made more colorful). Sweet and simple.
True Ways: In general I like the Idea of this, but not particularly its implementation. For one, I'm not a big fan of some of the sins (really, I only like the ones for the order or fellowship). RoK civs being penalized for having too much gold is a horrible idea, and would destroy the Khazad. Since they value hard work, perhaps having idle workers/having cities focus on generating culture/research/gold instead of building something real would be better? I don't now, it still isn't a great implementation. The Empyrean is a rather peaceful religion, so it shouldn't penalize those who refuse to declare war. It values fairness an equality and condemns ego, so its sins should be more like making an arrogant demand, refusing to negotiate when someone is asking for peace, not liberating cities, and having too many vassals.
Take the Palace: Nice. I always wanted a way to keep a captured palace (without resorting to worldbuilder). However, I'm not a huge fan of the diplomatic effects. I would prefer something like a chance that the civ would agree to become you vassal. It would also be nice if the civ that had its palace captured would not get a new palace elsewhere, leaving it without a capital. Then, if it cannot regain its capital within a few turns then the civ would be in danger of collapsing completely, leaving its other civs as barb cities, or making them revolt and join the nearest civ (if they had foreign culture). If they do retake their capital, it could be a huge morale boost and turn the war in their favor in some way or another (not quite sure how. Perhaps a morale promotion for all units? and/or a golden age?).