Rhystic Study Those aware of Rhystic Studys Commander dominance may be surprised to hear that this card was originally printed as a Common
Filter lands are great in multicolored decks that want to ensure they have access to the right colors of mana at all times
Scourge of the Throne gives you one when you attack the player with the most life, Hellkite Charger, and Aggravated Assault both give you extra combat by paying mana, and World at War, Waves of Aggression, and Relentless Assault are all sorceries that give you extra combat (the former two being able to be used twice)
Jyoti, Moag Ancient Jyoti, Moag Ancient is the backup commander to Omo, Queen of Vesuva
Rather than being primarily about reprinting expensive cards, the Challenger Decks are designed to give players decks that are at least Friday Night Magicplayable right out of the box and, ideally, legitimate top-tier Standard decks after a handful of upgrades
In a deck with eight enchantments on the battlefield, that's eight mana off a single creature