Getting to shave a mana off of Fervor in exchange for a little risk on losing it when the creature dies is an interesting design, and I hope to see just a little more of this
9 Jenova, Ancient Calamity Adds Value To Sacrifice Builds Green And Black Sacrifice Decks Are A Common Archetype Jenova, Ancient Calamity would make a good Golgari sacrifice commander , thanks to her consistent source of card draw
Thantis, the Warweaver is somewhat interesting as a Jund Spiders commander, although as a creature, it's mostly just a big creature that is likely to get you killed if you're not prepared by forcing opponents to attack
Light on the other hand tackles defensive dorks like Courser of Kruphix and Wall of Omens more effectively
With the handful of demons in this deck, he can potentially draw you a few cards when he enters the battlefield using his Prince of Chaos ability and he can leverage his status as the Lord of Torment in order to have your other demons dole out big damage when they enter the battlefield