Step 3 is to look over the new mechanics of Outlaws of Thunder Junction. Outlaws of Thunder Junction introduces the concept of crimes. Any spell or ability that targets an opponent, or their stuff (spells, permanents, hand, library) is committing a crime. Since this is a plane of outlaws, committing crimes is incentivized, not punished. In the villain set, you get to be the villain.
The set also introduces the plot mechanic. It’s similar to both foretell and suspend. When you pay a card’s plot cost, it goes into exile, and you can cast it on a later turn without paying its mana cost (as a sorcery). Plot can be used to hold cards up for explosive turns, but your hand’s on the table: opponents can see the plotted cards and plan around them.
Saddle is a keyword ability associated with the new Mount creature type. In a similar way to the Crew ability, it is activated by tapping any number of creatures you control with total power equal to or greater than the saddle value. Creatures with saddle, unlike Vehicles, can still attack and block like normal, but they have powerful abilities that only trigger when they become saddled or attack while saddled.
Finally, spree is a keyword found on instants and sorceries that grants them modality in a very similar way to escalate. Spells with spree have several effects, each with an additional cost. However, these costs can be different from each other. A spell with spree can have a very different impact when it’s cast in the early game using cheaper effects than when it’s cast as a finisher going all-out on expensive effects.