Aether Meltdown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature or Vehicle
When this Aura enters, you get {E}{E} (two energy counters).
Enchanted creature gets -4/-0.

Hedge Shredder

Whenever this Vehicle attacks, you may mill two cards.
Whenever one or more land cards are put into your graveyard from your library, put them onto the battlefield tapped.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Oviya, Automech Artisan

Each creature that's attacking one of your opponents has trample.
{G}, {T}: You may put a creature or Vehicle card from your hand onto the battlefield. If you put an artifact onto the battlefield this way, put two +1/+1 counters on it.

Xyris, the Writhing Storm

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris deals combat damage to a player, you and that player each draw that many cards.

Chandra, Spark Hunter

At the beginning of combat on your turn, choose up to one target Vehicle you control. Until end of turn, it becomes an artifact creature and gains haste.
+2: You may sacrifice an artifact or discard a card. If you do, draw a card.
0: Create a 3/2 colorless Vehicle artifact token with crew 1.
−7: You get an emblem with "Whenever an artifact you control enters, this emblem deals 3 damage to any target."