izigame.me

TLDR: Overall, I like this DLC. I personally really like seeing the final Dragon form ascensions, with Order and Astral ascensions being my favorite by far. While hard to utilize for many roleplay scenarios, I still think the two tomes are good, which the second having more freedom to be rotated into other empires; but for nature, I think Evolution is a must. Having the spiders, (which I feel are the most common evolve unit) actually reach their greater form is really good.
The Long:
I bought Season pass 1, out of the four DLC, Empires and Ashes is the only one, personally, that I will be not recommending. For additional context, I only play single player, usually with maximum players and largest map distance. I do not pick what is the strongest, I pick and build characters based on roleplaying for said character.
I'm going to assume you read the DLC page and will skip what's included and go to details.
The Tome of Evolution while being extremely good for nature, feels mighty out of place for anything else. There are five items in the tome. Summon (evolvable) wyvern unit, a buildable (evolvable) 'salamander' unit in your cities, a healing spell that is mediocre on most units, but insanely good on evolvable units, an enchantment that helps evolve units survive by giving them 20% bonus exp and a passive called slip away, which if they take fatal damage they teleport 3 hexes and heal 15HP (1 time per battle), and a minor draconic transformation that makes all of your cultural units have more hp as they gain experience, making them much hardier. As someone who picks things based on roleplay, this is extremely hard to roll into any non-nature/animal focused character. However, as said, it is absurdly good for said builds. Most 'baby' units that evolve, usually become very good and the enchantment helps them to survive to that point. Like the enchantment and healing spell would also be good on elementals, but the elementals are so spread out to various other tomes and also making the other dragon-themed stuff fit is what I mean by hard for someone who sticks to thematically roleplaying characters.
Tome of Dragons is ironically better for chaos, or warmongering, or fire focused characters and not so much for nature/animal, at least in my opinion. Flamer focus gives mage units a very good 1 hex aoe bomb that also bleeds and burns. Purifying flame is a good healing spell that heals in 1hex aoe and removes all negative status. After the siege rework it gives a pretty good Dragon Attack offensive siege that will damage and weaken the defenders by burning their defenses and setting things on fire making it harder for them to harass you from their walls. It gives you the ability to make 'baby' dragons in cities, that will scale and evolve into very powerful dragons. And lastly has the major Draconian Transformation which I while I don't like the visual look of, because it has holes in the wings for some reason, it does give the very powerful natural regeneration, which means you heal 10% HP at the end of combat turns and you also heal 10 additional HP on the world map; meaning much less downtime and you can keep your tempo and pressure up.
Lizardform is one of my most hated forms, not because of appearance, but because it's default racial form has "Poisonous"; which means any melee attack against (Default) Lizardfolk has a 60% chance of being poisoned; which stacks up to five times. Fighting a full 18v18 against Lizardfolk is specifically why I do not like them. But, at least I have several characters and such that I was able to make from the Lizardform, so, although I hate them as enemies, they get a pass for actually being used by me which is more than I can say about some forms.
Lastly, is the Dragon Ruler type. With the addition of the Dragon, there are 3 ruler types, Champion, Wizard King, and Dragon. I personally believe that Dragon is the strongest by far, because it's economy scales infinitely. Dragon Rulers have a passive that is gives them gold for each unequipped item your empire has, with higher tier items giving more gold. As stated, I only play singleplayer, higher-highest players on max land size. The late game economy of Dragons is unmatched even without building society traits to bolster it. I think as far as initial power, Dragons may feel weak, especially if the enemy has range or polearms because as a giant target you're easier to hit by range and take more damage from polearms. Late game, your powers become very powerful that I believe outscales all other rulers (including Eldritch Sovereign). This is based on it's unique strengths and not even necessarily the classes which are available to all (except Eldritch).