if you assume, on average, you're drafting 31 playables for your deck (23 spells, 5 lands, 3 sideboard cards) then approximately 10% of your cube could potentially be strong sideboard cards and the resulting decks would be 'more powerful' than a cube with no sideboard cards
Meanwhile, in Aether Revolt , we see the Consulate crack down after the confiscation coup, Pia launches the titular Aether Revolt, Baral
This decklist also has an alternative way to win via Thassa's Oracle if your library is nearly empty, which dredge enables
What we can do is more useful than pointing you to shady sources: show you the ethical alternative: clearly disclosed proxies for casual play and playtesting explain why counterfeits exist and why theyre risky show you how to spot them The Appeal of Counterfeit MTG Cards (and the real cost) Counterfeits exist because certain cards are extremely valuable
Check with your local game store to see when and how you can join in-store events featuring Mystery Booster: Convention Edition