Specifically, the mana value of Korvold, Gleeful Glutton is always 8
The discard effect from this doesn't happen until the end of that turn and it is on the seven new cards not the old hand meaning you need to rawdog the thing you want in the bin or have used a Brainstorm or Vampiric Tutor style thing to set it up
P/T Number 323 Language English Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pioneer, Standard, Timeless, Vintage Rulings (6/6/2025) The token copies exactly what was printed on the original enchantment (unless that enchantment is copying something else or is a token
P/T Set Number 36 Language Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pioneer, Standard, Timeless, Vintage Rulings (6/6/2025) Saga creatures have two sections to their text boxes
But it pays you back, creating a tapped treasure token for each mana from a desert used to cast it