Yugis deck may not be the most powerful, but he has plenty of good cards in the deck, such as Swords of Revealing Light, Gold Sarcophagus, and Monster Reborn
It offers multiple packs of: 10 Pack Hourglass 10 Pack Hourglass x6 10 Wonder Hourglass 10 Wonder Hourglass x6 This roughly translates to 7 extra booster packs and 6 extra Wonder stamina
With the reintroduction of the long dormant Ace Spec card type, Pokemon Temporal Forces has the potential to shake up the meta game quite a bit, just based on those new (and returning!) cards alone
It's also important to note that Marneus's draw effect is not a 'may' ability, and many of our token-producers can be triggered by opponents, so we can lose to your own hubris which, in my opinion, is the best way to lose in Commander
Skull Archfiend of Chaos This card only has two effects, but both of them are very beneficial to the decks gameplan