Acorn cards will also be those in Un-sets that may be difficult to balance for competitive formats. As seen with Killer Cosplay, the issue with its tournament play is its complexity, as it requires players to know every mana cost in MTG
Its ward cost is one of the most unique because instead of paying life or mana, opponents have to sacrifice a legendary artifact or creature
Ruby cards focus on offensive strategies, like using the Rush (able to challenge the turn the character is played) and Evasive (only allowing other Evasive ability characters to attack the character) abilities
Your characters often gain the ability to summon powerful allies to assist them temporarily in battle
Den of the Bugbear is custom-built as a mana sink for aggressive decks, generating two attackers, one of which has a potentially relevant creature type, for only four mana
On its own, Avenger of Zendikar is great: making lots of plant tokens that get bigger just for doing the thing green does best is powerful