Expansions overview?

[ICEunicorn]

I'm new to this game, where can I find detailed summaries of each expansion?
If I'm not mistaken, there are 13 expansions and 5 promos. Does each expansion only introduces new cards (which I can see in the gallery), but no new rules, is that correct?

[MarioFanaticXV]

Some expansions do introduce new rules. The first six sets were done as alternating between large and small releases- small releases could be played on their own at a 2p game, but were meant more as expansions for the previous large set.

Chronicles of the God Slayer, 10th Anniversary, and Return of the Fallen are the most basic sets, there's really nothing special about them, but they're good for learning the game. CotG and 10th are mostly the same other than art, but 10th does have some minor balance changes as well. Because of how basic they are, they mix well with other sets.

Storm of Souls and Immortal Heroes introduced events, trophies, and fanatics. Events go in the purchase deck and when one is revealed, it's played and effects all players. Certain mosnters now have "trophy" effects- you take them when you defeat them, and can discard them during any of your turns to activate their trophy effect. Fanatics are basically cultists that are a little stronger, but also act as trophies- events in these sets also have a special ability you can activate by discarding a fanatic- but you can only have one fanatic as a trophy at a time. Immortal Heroes also introduced (and I believe is the only set with) the Soul Gem deck; Soul Gems are cards you would gain randomly from certain effects, but could only be used on that turn. They were all copies of other cards that already existed, and add a bit more swinginess to the game. These sets combine decently with others- events become a little rare, but this isn't a game breaker.

Rise of Vigil and Darkness Unleashed have a third currency: Energy. Many cards will be more powerful if you play enough energy to activate their secondary effects, including getting better rewards for defeating some monsters. Energy is not "spent", you simply have a pool that lasts until the end of your turn- so if you have 4 energy, you can activate all energy effects you have that cost 4 or less. Darkness Unleashed also introduce transformable cards- some cards would permanently change into more powerful versions when you have sufficient energy. Neither of these sets combine well with anything but one another due to energy becoming very diluted with additional sets.

After "Year 3", all future sets were meant to be more standalone; they were still able to be combined, but there were no "dedicated" expansions.

Realms Unraveled continued with the idea of transformable cards, but these were achieved in other ways- some monsters would become heroes which you added to your deck, while other cards required you to play two cards of the matching faction to transform them. It's also especially notable for having some of the craziest combos in the game, especially with Adayu the Tormented/Adayu the Serene, which is very likely the most broken card in the game. It also introduced multifaction cards which counted as two different factions at once. This one combines well with others.

Dawn of Champions gives each player a unique hero character at the start of the game. There are four in total, one for each faction. As you purchase cards from the matching faction, you get points to give them new abilities- including each having a unique card you get at 2, 3, or 4 points depending on the individual hero. It also has more multifaction cards. This one combines well with others.

Dreamscape introduced another currency: Insight. It also has a separate Vision deck, of which each player gets 3 at the beginning of the game which only they can buy via Insight. Unlike Runes and Attack, Insight can be stockpiled between turns. This one does not combine well with the others on this list- but Delirium and Deliverance both bring back the Insight mechanic, and it may work better with them (I've not played those two yet).

War of Shadows introduces a day/night mechanic. Every card in the market row is either light or dark- if there are more dark cards out, it's night, and if there's more light it's day. Some cards are stronger during the day, others at night. There's some really fun combos that can be done with this one, but again, it does not combine well with others.

Gift of the Elements introduces the "Empower" mechanic- when you purchase a card with this ability, you may immediately scrap one card that you played that turn. This means you'll be able to get rid of those starter deck cards faster than ever. It also has PRIME Direction, a Mechana Construct that acts as an alternate win condition- if a player has at least 8 mechana constructs out when they play it, they instantly win the game regardless of honor. It also brought back Events, but these work differently- you no longer have Fanatics or effects triggered by them, but players can pay a high cost to transform them into a hero. This set combines pretty well with others.

Valley of the Ancients has three "temple" cards which players can vie for control of. Each has a special ability that they give you access to, and the player that has them at the end of the game gets bonus Honor for them. Honestly, this is my least favorite set- the temple mechanics seem to heavily favor the player that goes last (they're worth 5-10 extra honor each, 20 if you get them all), and it's just not that interesting a mechanic anyways in my opinion. Also, it doesn't combine well with other sets.

That's all of the sets that are included in the "base" Steam version, save for the promos, of course.