Bad Wolf Bay

At the beginning of combat on your turn, exile up to one target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.
When chaos ensues, cards can't enter from exile this turn. Then planeswalk.

Bowie Base One

At the beginning of your end step, goad target creature controlled by the player to your left. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever chaos ensues, target creature gains islandwalk until end of turn. (It can't be blocked as long as defending player controls an Island.)

Bloodhill Bastion

Whenever a creature enters, it gains double strike and haste until end of turn.
Whenever chaos ensues, exile target nontoken creature you control, then return it to the battlefield under your control.

Aretopolis

When you planeswalk to Aretopolis and at the beginning of your upkeep, put a scroll counter on Aretopolis, then you gain life equal to the number of scroll counters on it.
When Aretopolis has ten or more scroll counters on it, planeswalk.
Whenever chaos ensues, put a scroll counter on Aretopolis, then draw cards equal to the number of scroll counters on it.

Aplan Mortarium

Byzantium Radiation — At the beginning of your upkeep, put an exposure counter on Aplan Mortarium. Then you lose life equal to the number of exposure counters on it.
Whenever chaos ensues, create two 2/2 black Alien Angel artifact creature tokens with first strike, vigilance, and "Whenever an opponent casts a creature spell, this permanent isn't a creature until end of turn."

Besieged Viking Village

All creatures have "Boast — {1}: Put a +1/+1 counter on this creature." (Activate only if that creature attacked this turn and only once each turn.)
Whenever chaos ensues, put an indestructible counter on target creature you control that attacked this turn.

Amy's Home

When you planeswalk to Amy's Home and at the beginning of your upkeep, you may exile a nonland card from your hand with a number of time counters on it equal to its mana value. If it doesn't have suspend, it gains suspend.
Whenever chaos ensues, time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)

Bant

All creatures have exalted. (Whenever a creature attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents its controller controls.)
Whenever chaos ensues, put a divinity counter on target green, white, or blue creature. That creature has indestructible for as long as it has a divinity counter on it.