While its static abilities are fairly impressive on their own stopping all of your green spells from being countered including your Elf creature spells its Allosaurus Shepherds activated ability that truly sets it apart
It gets menace from the commander, so it'd be likely to dish out some damage, but its milling would be a liability against another graveyard deck
You get some form of card advantage no matter what you roll, but a natural 20 (or a 20 heavily influenced by Barbarian Class and friends) lets you reanimate a creature and put an expiration date on its owner
As usual, prerelease events happened a week before this, with spoilers running a few weeks prior
40 creatures and 20 lands is the opposite of what you want to be playing Sin Collector against
Played within almost 50,000 decks, this two-turn clock is an icon in Commander, which should maintain its value