Sacrificing any permanent will not only grow Korvold's power and toughness but let you draw a card each time as well

Chaos Warp Target permanent (land included) is shuffled into owners library The owner reveals the top card of their library and if it is a permanent, they get to put it on the battlefield Wild Magic Surge Destroy target permanent (land included) Its controller reveals cards from the top of their library until they reveal a card that shares a type with the destroyed permanent and puts it on the battlefield Chaotic Transformation Similar to Wild Magic Surge, but this exiles and instead targets an artifact, a creature, an enchantment, a Planeswalker and/or a land (yes all 5 at once if you want) and then reveals cards from the top of their library until they reveal a card that shares a type with it and places it on the battlefield Chaos Wand Pay 4 generic and tap it: target player reveals cards from the top of their library until the reveal an instant or sorcery card you may cast that card without paying its mana cost Wand of Wonder This is like a better version of Chaos Wand in that each opponent reveals cards, not a single target opponent

The trouble is the balance of burn and creatures, which is perennially a tough nut to crack
While Asleep, your Pokemon cannot attack or retreat (unless a Trainer card or another ability allows them to)
Tarmogoyf could end up as low as $60-$70 for a while, but it still sees a ton of play in Modern and that should keep its floor pretty high