What is sett reroll set 7?

As an AI language model, I do not have recent information about Sett reroll set 7. However, in general, Sett is a champion in the game League of Legends, and reroll refers to a game mechanic where players spend in-game currency to change certain aspects of their gameplay. Set 7 would refer to the seventh set of champions released in the game's history. Players often use rerolls to increase the likelihood of obtaining certain champions or upgrades to their existing ones.