First, it coined the font ( Beleren, named after the planeswalker Jace Beleren), it added the shiny holofoil stamp to all Rare, Mythic, or otherwise valuable cards, and extended the black border to cover a large chunk of the bottom of the card to help with machine reading - a very useful feature for places like Twitch
And while he may only enable you to sacrifice one permanent per turn, team him with sacrifice engines like Viscera Seer, tokens or recurring permanents (like Bloodghast or the cat oven combo of Witchs Oven and Cauldron Familiar) to sacrifice, and drainers like Blood Artist and Mayhem Devil, and things snowball very fast
While its expensive to cast at five mana, Thought Prison immediately rips a card out of an opponents hand, so its never a dead card
If you do, conjure a card named Golden Egg onto the battlefield
Stay safe and draw well