What expansions are available in Ascension (and what do they add)?

✔: Works well with all other expansions
✘: Doesn't work well with all other expansions

Chronicles of the Godslayers
✔ This is the base-game. 100 cards.

Return of the Fallen
✔ Adds 'Fate' mechanic. 65 cards.

Storm of Souls
✘ Adds Events and Trophy Monsters. 101 cards. Good with 'Immortal Heroes' and Gift of the Elements.

Immortal Heroes
✘ Adds Events, Trophy Monsters, and Soul Gems. 69 cards. Good with 'Storm of Souls' and Gift of the Elements.

Rise of Vigil
✘ Adds Energy and Energy Shards. 130 cards. Good with 'Darkness Unleashed'.

Darkness Unleased
✘ Adds Energy, Dark Energy Shards, and "Transform" cards. 85 cards. Good with 'Rise of Vigil'.

Realms Unraveled
✔ Adds Multi-Unite, multi-faction cards, and "Transform" cards. 100 cards.

Dawn of Champions
✔ Adds Champion cards. 96 cards.

Dreamscape
✘ Adds the Dreamscape and Insight. 98 cards.

War of Shadows
✘ Adds Night/Day. 96 cards.

Gift of the Elements (paid DLC, for some reason)
✘ Adds Events, Infest, and Empower. 107 cards. Good with 'Storm of Souls' and 'Immortal Heroes'.

The promo cards each add a few powerful cards to the game. They all work with any expansions. A number of the cards are absurdly overpowered so I'd only recommend playing with them if you want a crazy, luck-based game.

You can view exactly which cards are added from the 'Card Gallery' in-game

Promo 1 - 10 cards
Promo 2 - 9 cards
Promo 3 - 9 cards
Promo 4 - 9 cards
Promo 5 - Adds portals. 32 cards