As opposed to versions of this mechanic that might care about mana value, this specifically cares about the mana spent, which incentivizes you to play the improved modes of tiered spells
In Commander it's absurdly strong, churning out treasure tokens whenever your opponents draw cards
All you need to do is cast or attack with Sephiroth, sacrifice one of your other creatures to draw a card, and each opponent will be forced to sacrifice a creature as well
MTG Goldfish Open the deck you want on MTGgoldfish and then select Export to Arena under the decks featured images on the left
Saskia the Unyielding is ultra-combative and allows you to hurt the pillowfort player while beating down elsewhere (or double up on the pillowfort player)
Bumbleflower turns hosting into quite an experience, and opponents will draw just as many cards as you given the triggered ability and no modifications