Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.) When Knight of the Mists enters the battlefield, you may pay {U}. If you don't, destroy target Knight and it can't be regenerated.
![Knight of the Mists [Visions] MTG Single Magic: The Gathering](http://www.undiscoveredrealm.com/cdn/shop/products/knight-of-the-mists-visions-mtg-single-magic-the-gathering-100750_1024x1024.jpg?v=1693811430)
