Many cards have Shift or abilities that rely on certain types and numbers of characters being in play (we're looking at you, Seven Dwarfs)
This is enough to meet your needs for storing and protecting cards and can perfectly match different themes and styles of your decks
Not only that, but it has early game versatility because you can tap it to add one mana should you be running short, want to ramp quickly to a huge beast or, lets face it, get Esikas Chariot out as soon as possible
Judge promos: Limited-edition cards given to certified Judges, often featuring unique art or foiling, can reach four figures
On the surface, milling ten cards in a turn for each of your opponents might not seem like much, but add in a few other unblockable creatures and maybe a few effects that let you steal your opponents high powered creatures to attack with, and suddenly everyone is milling tons of cards each turn
She also gives every other permanent you control indestructible as well