Final answer:
Brimstone's Sky Smoke (E) ability has a duration of 19.25 seconds, effectively used to block enemy vision in Valorant.
Step-by-step explanation:
The duration of Brimstone's Sky Smoke (E) ability in the game Valorant is designed to control areas and block vision. Once deployed, Brimstone's Sky Smoke will last for 19.25 seconds. These smokes are strategically used to obscure sightlines, allowing players to reposition, attack, or defend without being seen by the enemy.