Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Peace of Mind

Reaver Titan

Void Shields — Protection from mana value 3 or less
Gatling Blaster — Whenever Reaver Titan attacks, it deals 5 damage to each opponent.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Knight Paladin

Trample
Rapid-fire Battle Cannon — When Knight Paladin enters, it deals 4 damage to each opponent.
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.)

Greasefang, Okiba Boss

At the beginning of combat on your turn, return target Vehicle card from your graveyard to the battlefield. It gains haste. Return it to its owner's hand at the beginning of your next end step.

Thunderhawk Gunship

Flying
When Thunderhawk Gunship enters, create two 2/2 white Astartes Warrior creature tokens with vigilance.
Whenever Thunderhawk Gunship attacks, attacking creatures you control gain flying until end of turn.
Crew 2

Stronghold Rats

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.