Being slow is what makes this card so fair, you are looking at a long time before it is worth the card cost, usually it needs to flip
You are destroying $12-18 in sealed product per pack
The front side is most valuable in mono-colored or colorless decks that struggle with removal, while the backside likes multicolored cards, specifically two-color cards
On the downside, though, I'm starting to see a small and frustrating pattern
And be careful out there eldrazi are coming
Mairsil, the Pretender, on the other hand, lends himself to a graveyard-copy strategy, where you would want to fill you graveyard with powerful static or activated abilities from Creatures and Artifacts for Mairsil to exploit