Final answer:
Brimstone's Stim Beacon in Valorant is a signature ability that does not cost anything for the initial charge, but additional charges can be purchased.
Step-by-step explanation:
You've inquired about the cost of Brimstone's Stim Beacon ability in the game Valorant. Brimstone's Stim Beacon (Ability C) is one of his signature abilities and it does not have any cost associated with it. Each player starts with one free Stim Beacon charge at the beginning of each round. However, you can purchase an additional charge if needed. The core purpose of the Stim Beacon is to provide a temporary combat stim to Brimstone and his allies within its range, increasing their fire rate and reload speed.