YMMV / Mage Knight

• Demonic Spiders: The Draconum in general are ridiculously strong, with high Armor and Attack values coupled with resistances and special abilities. On top of that, they are Rampaging, so you cannot simply move around them, and they are often found close to cities, which you sometimes need to conquer to win them game.
• Goddamn Bats: There are a few enemies in the game who are both Armored (non-Elemental attacks are only half effective against them) and have an Elemental attack (Blocks that don't belong to the opposite Element are halved). If you only have non-Elemental cards in your hand, prepare to waste a ton of them and take some Wounds to get rid of the enemy.
• Luck-Based Mission: At night, you cannot see most enemies until you assault their stronghold. Therefore, it is possible to rush into a fight you have no chance of winning. Knowing which fights you can afford to take is fundamental in this game.
• Scrappy Mechanic: The rules esplicitly tell that you can go back and redo any action, provided that you didn't reveal any previously unknown information (so there's no avoiding fighting a monster token you just flipped, for example). While this is great for new players, who cannot possibly know which moves and card combinations are optimal and which ones are not, it can be painful for everyone else at the table, who is forced to wait while the player continues going back and forth, considering every possible option.