the end mtg card Endbringer - Oath of Gatewatch (Exile all spells and abilities on the stack Emrakul, the Promised End

Yes, mono-white can be good in Commander

The commander of your ship is Captain Nghathrod (who Ill simply refer to as Captain for this article, because Ill lose it if I have to type out Nghathrod 20 times), a 3/6 Horror Pirate that gives all of your Horror creatures menace

Barrin, Tolarian Archmage While Mangara was looking to shake off the pillow fort descriptor, Barrin has built himself a bouncy castle. While Barrin and friends are certainly equipped to deal with opposing threats, the Archmage incentivizes us to prioritize bouncing our own threats instead

Its also a common card for Pauper purposes

You could do something as simple as adding an extra -1/-1 counter to an enemy creature, or you could really ruin someone's day by doling out poison counters at an alarming rate