Its again deservedly high up on the list, as its super versatile and indispensable, at least in the sideboard of every black deck
This means that each of your powerful control spells can do double duty, being castable twice per game, significantly improving their consistency as well as your flexibility when choosing which spells to cast
Rather than aiming to take out opponents as quickly as possible, Control decks aim to 'control' the board, depriving opponents of key resources through removal and counter spells, preventing opponents from assembling their win-conditions while assembling a win-condition of your own
Four total players can join in the battle if two have pre-made decks of their own, using a higher-difficulty Battleground card
That efficiency is exactly why it remains one of the best black cards in MTG
The vast majority of the time, if youre in color and building a deck with Game Changers, Rhystic Study will be in the 99