These were first introduced in Zendikar Rising, and are cards that have two sides that can be played from either side
Commonly played examples include Aristocrats where you sacrifice something like Reassembling Skeleton to a mana free sacrifice like Ashnod's Altar and then trigger the Zulaport Cutthroat to hit all foes as your win-con or hitting with Guttersnipe and similar triggers in a Spellslinger deck for your instant and sorcery casts
Still, I recommend capping your fleet at three Spacecraft per deck
The Illusion Fox Pokemon's ability to transform into other Pokemon fit N's themes of questioning appearances and truth
Keep sacrificing the Myr Battlesphere and at least one Myr token to recur them endlessly, giving you infinite mana, tokens, and death triggers
Burakos, Party Leader The party mechanic hasnt gotten a ton of dedicated support, but Burakos, Party Leader is the choice to helm a party-themed Commander deck