Here are a few detail shots
For example, if you control Quantum Riddler and you cast Decode Transmissions while you have no other cards in your hand, Quantum Riddler's replacement effect will apply, and you'll draw three cards instead of two

Ajani Goldmane Ajani Steadfast Ajani, Adversary of Tyrants Ajani, Caller of the Pride Ajani, Nacatl Avenger Ajani, Strength of the Pride Ajani, the Greathearted Arlinn, Voice of the Pack Arlinn, the Pack's Hope Ashiok, Wicked Manipulator Basri Ket Basri, Devoted Paladin Chandra, Acolyte of Flame Chandra, Legacy of Fire Commodore Guff Domri, Chaos Bringer Dovin, Grand Arbiter Elspeth Resplendent Elspeth, Storm Slayer Elspeth, Undaunted Hero Garruk, Cursed Huntsman Garruk, Unleashed Geyadrone Dihada Gideon, Champion of Justice Gideon, the Oathsworn Grist, the Hunger Tide Grist, the Plague Swarm Huatli, Radiant Champion Jace, Arcane Strategist Jace, Unraveler of Secrets Jeska, Thrice Reborn Jiang Yanggu, Wildcrafter Kaito, Cunning Infiltrator Karn, Scion of Urza Kaya the Inexorable Kaya, Geist Hunter Liliana, Death Wielder Lolth, Spider Queen Nissa of Shadowed Boughs Nissa, Voice of Zendikar Ral, Crackling Wit Ral, Leyline Prodigy Sorin, Imperious Bloodlord Sorin, Ravenous Neonate Space Beleren Tasha, the Witch Queen Teferi, Temporal Pilgrim Tezzeret, Cruel Captain The Aetherspark The Wandering Emperor Tyvar Kell Vivien, Monsters' Advocate Vraska, Regal Gorgon Vraska, Swarm's Eminence

One thing I do want to call out is that out of the sets we had this year, we did have one set only that added cards to Pauper via downshifts and that was Innistrad Remastered at the beginning of the year
These last few years have done nothing but prove the potential that I saw in Shawn
Probably worth noting that Mike Long is notorious for a history of cheating in high-stakes MTG events, so maybe Rootwater Thief was his comeuppance