Getting four or five extra lands, at the floor, goes a long way to recasting expensive Commanders
Legendary Creature - Shapeshifter Orvar, the All-Form Changeling Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents
With plenty of effects to flicker your own creatures at instant speed, you can keep triggering her abilities on your opponents turns over and over again for tons of value
4 Slogurk, The Overslime A darker take on the Ooze concept from the nightmare plane of Innistrad, Slogurk nudges you towards an interesting land-centric playstyle
The Aether Revolt team played with reverse engineer, but it was ultimately killed for being a bit too problematic developmentally