extra upkeep cards mtg Timesifter (Mirrodin) Top 10 Cumulative Upkeep Cards

If you can reduce the casting cost, sneak it onto the battlefield, or reanimate it, you should have a tidal wave of value coming from the top of your library through your graveyard

On top of that, it also makes all spells your opponents cast cost one more to cast

In theory, they could show up in other kinds of booster in the future, but its unlikely as Wizards will want to keep something special for the most expensive boosters

Ensoul Artifact (Magic 2015), which depicts a giant pair of ensouled scissors rampaging across a marketplace: Too often, some self-described genius comes up with a "labor-saving device" that ends up creating far more work