It is highly probable that Cid is the protagonist of Clicker Heroes 2.Cid and Yachiyl both have 7 upgrades each, the most a hero can have.
Upgrade him to make your clicks more powerful.
All these names are exclusively female names in their respective languages, unlike the androgynous english Cid. Cid is called Cindy in the French version of the game, Ekkja in German, Cira in Spanish, Alice in Portuguese.Perhaps she was, at one time, also meant to boost overall DPS, and not just Click Damage. Even though Cid cannot be gilded by conventional methods, there is still a gilded sprite of her.
This was a reference to the character Gordon Freeman from the game series Half-Life, which is produced by Valve, the owners of Steam.