Examples of cards that have a lose the game condition include cards like Chance For Glory, Demonic Pact, and Nefarious Lich
I'd grab a pen and have some paper handy to write on so that if you need to make notes about things that are harder to track because they aren't as visible ("Okay, I have his Teferi's Protection exiled with my Spelljack" or "Erin's graveyard contains three cards she can cast from the graveyard"), you have easy access to doing so
Yawgmoth, Thran Physician FINAL FANTASY: Through the Ages, Mythic Limited: 4.5 The Emperor, Hell Tyrant (Yawgmoth, Thran Physician) asks if you have a lot of creatures in your deck, and in exchange, it delivers you plenty of match wins
Tinkaton can be obtained from Paldean Wonders Booster Pack in the Paldean Wonders Set
As the 30th anniversary celebrations continue, sets that include old favorites like Pikachu and the entire line of Eeveelutions are seeing massive price increases