mtg card cutter MTG-1220 (12") Guillotine Paper Trimmer (Paper Trimmers) You may attach this Equipment to it Cori-Steel Cutter》 Is the Best

Soul Shatter - Each opponent sacrifices their highest CMC creature or planeswalker, and its only 3 mana

I mean, the Alpha version

Doubling Season [Best Token Ramping Enchantment] When it comes to outscaling your opponent with tokens or counters, you cant go wrong with Doubling Season

Some people in the comments wished for them to be metal, but it doesnt look like well be getting them

You could also instead cast the Heartflame Slash adventure since it also matches the discover 3 restriction

With the right combination you can loop Core Prowler with Reveillark, Karmic Guide, and a sac outlet, netting plenty of proliferation after the initial infection