5 feels too expensive really for what it does
Xanathar, Guild Kingpin, for example, is the beholder at the centre of the Xanathar Thieves Guild and here allows you to steal other peoples cards straight from their libraries
Im a fan of protection spells that leave your board stronger than they were before the effect you needed protection from, and thats exactly the Mutational Advantage youre getting
No matter the incarnation of the spell, the structure is the same: you get a bonus for casting an instant or sorcery, and if you spend five or more mana you get an even bigger bonus
Were also in strong colors for reanimation, so we can go down the line of creatures with good enters-the-battlefield triggers and go ham
Tempo is the name of the game here, and Im not complaining