The sleeve size you should buy for 99% of decks For normal MTG play, you want Standard size outer sleeves , which are commonly around 66 x 91 mm
Katara, Waterbending Master rewards you like Sanctum of Calm Waters where the first counter gets you to a loot, but after that is pure card draw
With that in mind, here are the top 10 MTG best cards from The Lost Caverns of Ixalan for Constructed
People like to buy boxes to crack lots of packs, have higher chances of finding that special rare or mythic they need, or play Limited
Draw Punishers These are the decks bread and butter, the cards that take that long list of forced draw effects and translate them into a win condition
However, if a pattern emerges over time, it may suggest something else