mtg opponent draws a card Inzerva, Master of Insights Trade Secrets MTG - Onslaught

These two let you cast an infinite number of copies of Dramatic Reversal which in turn gives you an infinite number of Displacer Kitten triggers

These effects call under two broad categories: cards that return lands from the graveyard to the battlefield as part of a spell or activated ability (Tato Farmer, Splendid Reclamation) and cards that allow you to play lands from your graveyard (Crucible of Worlds)

Its a very popular Commander card and even subbed in as a viable replacement to Bogardan Hellkite when Dragonstorm was added to Historic

This is one of the cases where the market value of an MTG card betrays its true worth

Its an important distinction to make, because if a mechanic is not inherently broken in all cases (and very few are) then you can make the case for a new set figuring out how to implement them in a way which avoids the pitfalls of previous overpowered designs

The first is that Jamie McCrimmon has a useful combat ability, trample