Aside from looking like a badass, Ezuri is a four mana Green and Blue 2/2, that allows you to gain an experience counter whenever a Creature with power two or less enters the battlefield under your control
Not that that's a bad thing, especially when none of them appear to have FF7 Rebirth's creepily toothy design
Arbiter of Woe Rarity: Uncommon TYPE: Creature SUBTYPE: Demon CMC: 6 Mana cost: USD: $0.23 EUR: 0.18 TIX: 0.03 EDHREC RANK: 10288 (5/4) As an additional cost to cast this spell, sacrifice a creature
Because it drains the life of every opponent as a free upkeep trigger, and converts that to scrying, you're always using it to set up your card draw
Finally, when he swings you can force the defender to sacrifice an artifact that triggers his second ability
Its easy to see these uncastable spells as leaving power on the table, but so far, results show that having the chance to play them is more likely to distract you from your singular, cyclical goal