Running Eivor out into open mana is a death sentence, so either wait until your opponents are tapped out or hold off until you can hold up your own protection spell in case things go wrong
Its especially useful if you collect across multiple games because it unifies your entire inventory into a single portfolio
In addition to that, they are treated with a special status, being given a number above the sets cap, as well as a rarity that makes them valuable
Each deck only contains 20 cards, so players may not have to search for long to obtain cards for one
However, only one of these can be in a deck, and it can only be used once in a battle
Many of my colleagues recommend against having firm sideboard plans, instead emphasizing improvisation and flexibility