Seek Bolas's Counsel is a rare Sorcery card from Mystery Booster Playtest Cards 2019 (CMB1), collector number 98. Current market price: $0.98, TCGplayer market prices via Scryfall.
Choose one at random — • You get an emblem with "At the beginning of your upkeep, pay {U}{B}{R}. If you don't, you lose the game." • Each player discards their hand. • Planeswalk to Pools of Becoming. (Once there, you can roll the planar die only if you're playing Planechase.) • For each opponent, exile cards from the top of their library until you exile a nonland card. You may cast those cards without paying their mana costs. • Destroy all creatures and non-Bolas planeswalkers. • You get an emblem with "You can cast nonland cards from your sideboard."