Best Archetype Creature Payoffs Keyword-Matters Wizards has added more keyword support over the years, with direct callouts to certain evergreen mechanics
Beast Whisperer and Soul of the Harvest are two perfect examples, which each effectively add Elvish Visionarys text box as a cast trigger to every creature in your deck
A combo can be any set of cards which effectively ends the game in your favor, be that a prison like Teferi + Knowledge Pool, infinite damage/mill, or even a very fast combat clock like Skithiryx, the Blight Dragon + Lightning Greaves
Sidisi, Brood Tyrant helped define this wedge in the original Khans of Tarkir and will mill three when it arrives or attacks, and then when one or more creatures are put in your graveyard from your library, you make a free 2/2 Zombie token
There are several Mewtwo cards in this set, so it will be interesting to see where this card lands in terms of price point