While there aren't a ton of sacrifice payoffs available at lower rarities, the high rarity has cards like Sephiroth, Fabled SOLDIER and Zodiark, Umbral God as fantastic top-ends
Essentially what this does is that before damage, your opponent loses 2 life if they block your Slivers and that means theres a chance if you hit for exactly enough Afflict, they can block all they want, the combat step will just end before damage
On top of this, whenever you deal toxic damage to your opponent using a creature, you add another poison counter to their total count
But what if we told you that there
Spend this mana only to cast a Dinosaur spell or activate an ability of a Dinosaur source
Haunted Angel Linvala, the Preserver Seraphic Steed Soul of Emancipation The Book of Exalted Deeds The Pit