Final Showdown

Spree (Choose one or more additional costs.)
+ {1} — All creatures lose all abilities until end of turn.
+ {1} — Choose a creature you control. It gains indestructible until end of turn.
+ {3}{W}{W} — Destroy all creatures.

Crawlspace

No more than two creatures can attack you each combat.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Propaganda

Settle the Wreckage

Exile all attacking creatures target player controls. That player may search their library for that many basic land cards, put those cards onto the battlefield tapped, then shuffle.

Onakke Oathkeeper

Creatures can't attack planeswalkers you control unless their controller pays {1} for each creature they control that's attacking a planeswalker you control.
{4}{W}{W}, Exile this card from your graveyard: Return target planeswalker card from your graveyard to the battlefield.

Magus of the Tabernacle

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay {1}."

The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Teferi, Master of Time

You may activate loyalty abilities of Teferi on any player's turn any time you could cast an instant.
+1: Draw a card, then discard a card.
−3: Target creature you don't control phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
−10: Take two extra turns after this one.