Battle Myrsphere

When this creature enters, create four 1/1 colorless Myr artifact creature tokens.

Whenever this creature attacks, you may tap X untapped Myr you control. If you do, this creature gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, shuffle it into your library and draw a card.

Menace

When Chancellor of the Mulligan enters the battlefield, draw three cards. When you do, any number of target players mulligan. (They shuffle their hand into their library, then draw that many cards and put one of them on the bottom of their library.)

Flying

Whenever this Vehicle deals combat damage to a player, put the top two cards of that player's library onto the battlefield face down under your control. They're 2/2 Cyberman artifact creatures.

Crew 4

As this creature enters, choose a creature type.

When this creature enters, reveal the top four cards of your library. Put all creature cards of the chosen type revealed this way into your hand and the rest on the bottom of your library in any order.

Creatures of the chosen type get +1/+1.

+4: Target player exiles a card from their hand.

−3: Exile target permanent.

−14: Restart the game, leaving in exile all non-Aura permanent cards exiled with Karn. Then put those cards onto the battlefield under your control.

When this artifact enters, destroy target permanent.

When this artifact is put into a graveyard from the battlefield, return it to its owner's hand.