Most extra turn spells are in Izzet colors, and copying them allows you to essentially take enough extra turns to win the game easily
Both Uro and its counterpart, Kroxa, Titan of Death's Hunger, made an impact in Modern, but what made Uro extra busted was the fact that its ability to draw you a card often meant that it found you more cards to fill your graveyard for the next time evert time you cast it
If you are going mono red then these cards start to look interesting, if you are just splashing black for Cutthroat and Artist then again, looking quite reasonable
This means on average this is more of a stall card than a win condition
As a sorcery, you may pay the mana cost of a locked door to unlock it.) If multiple effects modify your hand size, apply them in timestamp order