(I would like to think that Unsubstantiate for only spells would be common because it's very much worse than multiple uncommons.) Meanwhile, Comply is also unique, but it certainly isn't rare, considering that Silence costs the same amount of mana and keeps an opponent from casting anything for a turn, while Comply requires you to "guess the right card" for it to have any effectand even if you guess right, it only stops one card
Both seem like they are going to be great, so you probably cant go wrong
You can play these opponents multiple times to earn free cards and packs to help build your collection
Indestructibility is a bit slow at four mana, but not terribly so
The art is breathtaking, and the sheer power is enough to turn the tide of almost any battle
Don't think that putting your money into Magic cards today is going to pay for your kids to go to college, or pad your retirement until you talk to a professional, and also carefully ponder the next question