Riverchurn Monument is the kind of mill card that scares me, because it tends to combo with a bunch of mill favorites like Bruvac, Phenax, God of Deception, and ways to make players mill a lot of cards (Maddening Cacophony, anyone?)
I still got my kicks playing Sealed at prerelease, and going 3-1 or better each time had me thinking I was just as good at Limited as ever
Mystical Tether is a very solid white removal spell, and the instant speed mode makes playing against white quite more complicated
There is an Amethyst/Steel deck with cards focused on Jafar and Iago from Aladdin , as well as a Ruby/Sapphire deck starring Belle and the Beast
From rare editions to exclusive prints, these cards are worth more than some people's annual salary