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 (Paul McCabe) (SB) [World Championship Decks 1997]](http://tothetablebgc.myshopify.com/cdn/shop/files/97a57658-46cf-4bb0-a714-ae3ab7b326ef_8dbba63f-8942-4e3d-b682-ebaa556459be.png?v=1776354944&width=1445)
