(first time poster here, plz forgive if format is bad)
This aims to be a simple guide on my setup that lets you steamroll the entire game's combat, though technically you can always just spam Devil Cards to win any battle (if you don't care about Eldritch levels.)
My preferred setup is double-Heaven (top-left), which lets me deal exactly 60 damage by playing just 8 cards.
- Burn Fresh Air -> Chant: Person x2 -> Chant: Earth x2 -> Backwater -> Chant: Heaven x2.
(I'm using a second Chant for convenience, but the starting deck's Refurbishment can be used instead.)
This setup literally wins all but one encounter with 100% consistency (w/ +3 Mana Regen). But if you don't have enough Mana, you can instead use additional Fast Step cards. Still a 100% consistent strategy, but the playing order gets a bit trickier.
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That said, before you can get all the 3★ cards needed, you might have to fight normally, or use a few Devil Cards to get through. Note that each three Stage Bosses guanrantees four 3★ cards to pick from, and of course you can save-scum these. Use Stage 1 boss for easier fights, letting you grind for 3★ without difficult encounters that might raise your Eldritch Level too much.
Alternatively, the other two Turn-1 setups (30 or 40 damage) are still pretty good, and should get you through most encounters in Stage 1 and make grinding cards easier. You might still need a Fast Step card, on top of the Chant & Backwater.
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Lastly, I want to talk about how I dealt with the only encounter in the game with 60+ HP, which is the final boss. Back then, I accidentally discovered a cheese-strat, so IDK how a "proper fight" should go. Regardless, lemme quickly go over my strategy. (middle-right setup)
Baiscally, use Transformation to steal Mocking Refrain (
screenshot) from the boss to delete all their Mana. From there, just keep reviving that card using Tiheera. You do need to keep sacrificing generated cards, which I'm using the Fox Fire here. Technically Vials of Breeze work better with Tiheera, but it doesn't matter here.
Also 100% consistent! No +Mana relic needed from the Ritual mini-bosses either.
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Oh and generally speaking, for builds that don't involve reviving cards, Fast Step and Courage are always useful for more consistent cards cycling & Mana management. It's not mandatory for my builds though, so I just intentionally avoid the Courage relic in my 2nd playthrough. (You cannot get rid of them or remove the Courage cards, which can annoyingly clog up my hand)
The Stage 3 is also good for grinding cards. Not only is there a rare room on Floor 2 (Library of the awaiting) that gives guanranteed 3★ cards (from interacting with the books), the final floor also contains a gauntlet of bosses that drop many good quality cards. Maybe I'm hallucinating, but cards still missing in inventory seems to appear more often.
Oh and I find that when there are too many cards in the enemy's Draw Pile (50+ cards), they would immediately take 1000+ damage and instantly die, which is so funny to watch. It's like Mounting - Both kill the boss by making them too horny.
(I also tried the Discard strat, i.e. Shikigami spam, but it's not as effective or funny)
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Honestly the gameplay in this game is surprisingly fun and has lots of depths. It's a really unique spin to deckbuilding games and I really enjoyed it.
Lastly, let me share with y'all a compiled list, of all 150 obtainable cards, confirmed by yours truly. If you plan on collecting them all, I attach some simple instruction on using it inside the TXT as well. Enjoy!