Cards that are frequently used in winning decks tend to increase in value as they become more sought after
Call of the Ring If you play this on turn two, youll complete the Ring by turn six and have the chance to draw four extra cards
These usually have the same art depictions seen in the full art printings of the cards but instead of having the original colors, everything is dipped in a rainbow foiling
Takahashi, Kazuki (October 10, 2005)
The problem with walkers is not having four mana but having four mana spare after you create a board in which a planeswalker won't just die
a devil King has to be pretty badass to get that position, some formats keeps Kings off the field unless they volunteer, and it's demonstrated that a side that loses nearly all their pieces before managing to bag the enemy King can still lose points overall