It is a protective sleeve to insert each card to protect it from scratches
Mountains: This red mana casts aggressive spells and creatures meant to beat your opponent by the quickest means necessary
Once flipped, she comes in at a fairly low two loyalty counters, but as soon as you use her first ability, which protects her from attacks, you tick her up to four counters, and positions her outside most damage-dealing removal spells
The goal of the build is to control the board state while ramping into big Characters that Quest for three Lore at a time or Challenge an opponents troublesome Character
Manaforge Cinder: a good way to solve early game mana screw of a specific color, especially early in a Limited game
Either way, we've updated this list with the new king