Note the Rebels featured an ability where they searched up the casting cost chain, so you could tap the Sergeant for a 2-drop, 2-drops could search for three drops, and such
It is annoying for control players to deal with and a pretty good defensive chump to handle aggression with
Summary Start with pre-constructed decks to learn game mechanics and strategies before building your own
Farewell Board wipes are useful because they reset the board, and few do it better than Farewell, which doesnt even leave your opponents mana rocks to rebuild with
Still, it can't be understated that these cards are among the easiest to play and the most powerful in the game
The "only once each turn" restriction applies to each ability individually, even if multiples of the same card were exiled to craft Locus of Enlightenment