Slay The Spire is one of Steam's latest Early Access gems thanks to its polished combination of roguelike dungeon crawling and traditional card game mechanics. The game's quite challenging at first, but some players have already been discovering special combos that allow them to rip through the game with ease.
Twitch streamer RiskyCB is one of those people and he recently uploaded a highlights video of his exploits to YouTube that was spotted by Rock Paper Shotgun. In it he works at shrinking his deck down to only two cards which synergize to enable a deadly combo from the very first turn in any fight.
Usually during a playthrough of Slay The Spire the point is to slowly build up a strong collection of new cards gained after winning battles. RiskyCB
though focused heavily on dumping starting cards, something you can pay merchants for as well as accomplish with various abilities and items. Late into his playthrough this allowed him to employ a deck with literally only two cards: Flash of Steel and Duel Wield.
The first is zero-cost, deals six damage, and allows you to draw another card. The second makes copies of the other cards in your hand. From there RiskyCB is able to get into an infinite combo where he just cycles through Flash of Steel endlessly until whatever he's fighting is dead. The combo is broken, clearly, but requires so much effort and luck to arrive there (stripping your deck down to just two cards is incredibly difficult).
Since the game's still in Early Access it will be up to the developers how they decide to balance strategies like this, but since it's a single-player RPG it's fun to see all of the unique ways players find to break the game and completely overpower its bosses. I've been playing a lot of Slay The Spire and can't recommend it enough.