At the time of writing, there are 226 unique cards (plus around 14 additional "promo" cards) available, split across three choices of pack (one each themed after Charizard, Mewtwo, and Pikachu) and all together making up the game's first expansion
Twenty Revised cards were originally in the Arabian Nights expansion, and another nineteen were originally in the Antiquities expansion
Commander players will be happy with Kamigawa: Neon Dynasty, as head designer Mark Rosewater confirmed on the stream that the set has a Legends theme, and has a "higher than normal" number of Legendary creatures for a premiere (Standard-legal) set
Maybe theres an Uncle Istvan in the woods just outside your house
If you cast only one half of a split card, you only consider that half's mana value while it's on the stack
You may not be the "owner" of more than one Merc at a time from your own payment (although you can control more than one by stealing others)