Firstly, it's only two mana, making it cheaper than almost every other ETB sacrifice creature that sees play
Draft decks can't instantly fill the graveyard for such effects, unlike Constructed decks like Goryo's Vengeance decks in Modern
GUIDE THE DEAD TO GLORYOn the plane of Amonkhet, the dead never rest
The effect is hilarious, too, forcing the opponent to guess the illustrator of a card
You already knew I was writing about my top 10 Time Counter cards, and not just from this column's title
The tiny opportunity cost means you may not need a heavy defender theme to make Coral Colony viable, but it obviously helps and also provides another way to kill opponents using Axebane Guardian + High Alert untap loops