Did someone say discard
Grist, Voracious Larva / Grist, the Plague Swarm When building around Modern Horizons 3 s Grist, Voracious Larva, I think you want to lean into a sacrifice deck using cards like Reassembling Skeleton, Forsaken Miner, and Bloodghast for sacrifice fodder
You might get your inner sleeves on Phyrexian Tower, Urza's Incubator, or fetches like Wooded Foothills, and those are among the reprints
I also love Tergrid in a deck that can play Sire of Insanity
Passionate Archaeologist is likewise almost an auto-include in any heavy impulse draw based deck
Im often critical of the curation of some of the digital Cube offerings for featuring too many red five-drops, and thats because Id rather have a mana sink like Den of the Bugbear to give me things to do when I flood than a bunch of stuff like Goldspan Dragon and the intention to get to five mana in every game