Similar to other cost-based counterspells like Syncopate and Spell Stutter, Confounding Riddle will counter an opponents spell unless they can pay an additional four mana
Teferi, Master of Time Teferi comes in several special-edition versions in Core Set 2021 its his set, after all but we prefer the borderless printing with art by Chris Rallis

Venusaur V swsh35-1 Weedle swsh35-2 Kakuna swsh35-3 Beedrill swsh35-4 Eldegoss V swsh35-5 Vulpix swsh35-6 Victini swsh35-7 Incineroar V swsh35-8 Sizzlipede swsh35-9 Centiskorch swsh35-10 Carvanha swsh35-11 Sharpedo swsh35-12 Wailord V swsh35-13 Drednaw V swsh35-14 Drednaw VMAX swsh35-15 Gardevoir V swsh35-16 Gardevoir VMAX swsh35-17 Hatenna swsh35-18 Hattrem swsh35-19 Hatterene swsh35-20 Galarian Cursola V swsh35-21 Alcremie V swsh35-22 Alcremie VMAX swsh35-23 Machop swsh35-24 Machoke swsh35-25 Machamp swsh35-26 Lucario V swsh35-27 Zygarde swsh35-28 Rockruff swsh35-29 Lycanroc swsh35-30 Rolycoly swsh35-31 Grapploct V swsh35-32 Ekans swsh35-33 Arbok swsh35-34 Galarian Zigzagoon swsh35-35 Galarian Linoone swsh35-36 Galarian Obstagoon swsh35-37 Absol swsh35-38 Purrloin swsh35-39 Liepard swsh35-40 Scraggy swsh35-41 Scrafty swsh35-42 Trubbish swsh35-43 Inkay swsh35-44 Malamar swsh35-45 Nickit swsh35-46 Duraludon V swsh35-47 Swablu swsh35-48 Altaria swsh35-49 Drednaw V swsh35-69 Gardevoir V swsh35-70 Galarian Cursola V swsh35-71 Grapploct V swsh35-72 Charizard VMAX swsh35-74 Drednaw VMAX swsh35-75 Gardevoir VMAX swsh35-76 Charizard V swsh35-79 Bede swsh35-50 Full Heal swsh35-51 Great Ball swsh35-52 Hop swsh35-53 Hyper Potion swsh35-54 Kabu swsh35-55 Marnie swsh35-56 Milo swsh35-57 Piers swsh35-58 Pok Ball swsh35-59 Pokmon Center Lady swsh35-60 Potion swsh35-61 Professor's Research (Professor Magnolia) swsh35-62 Rotom Bike swsh35-63 Rotom Phone swsh35-64 Sonia swsh35-65 Suspicious Food Tin swsh35-66 Team Yell Grunt swsh35-67 Turffield Stadium swsh35-68 Hop swsh35-73 Kabu swsh35-77 Piers swsh35-78 Suspicious Food Tin swsh35-80 Set Analytics Cached pricing and usage signals for cards in this set

at four CMC, I don't expect to be casting her more than two or three times in a typical game
this turn, your opponent cannot activate Spells, Traps, Spell/Trap effects, or Monster Card effects when a "Gishki" monster is Ritual Summoned, or when a "Gishki" Ritual Spell Card is activated