Final answer:
In Valorant, Viper needs a minimum of 20 fuel units for initial activation of Toxic Screen (E), draining at about 10 units per second during use.
Step-by-step explanation:
The minimum fuel required to cast Viper's Toxic Screen (E) in the video game Valorant is a basic concept within the game's mechanics. Viper, one of the agents in Valorant, has abilities that are fueled by her toxic gas resource. To activate Toxic Screen, Viper needs to have at least 20 fuel units. The screen starts by consuming 20 fuel upon activation and then it continues to drain at a rate of approximately 10 units per second. When the fuel reaches zero, the screen deactivates automatically and the fuel begins to recharge when not in use. It is important to manage this resource carefully during gameplay to make effective use of Viper's abilities.