Colossus appears in All-Out and Electron. It is a colossal robotic that can shoot lasers, massive fire balls, missiles, and Drones.
Most of the boss attacks are vital and give instant death to the players. A lot of instant respawn and health recovery items are required. Titan Doll costume is also a bonus because it can avoid instant death.
The boss can shoot numerous missiles towards player and they are fast. However, the missiles can be destroyed with firepower.
At a regular interval, two XT-300s will drops onto the battlefield and slowly damage the player with its rocket explosion splash damage and minigun. Destroy and mount them to give stronger defense and survival.
At a regular interval, drones are launched from the Colossus and damage the player with its sentry guns. Don't mind shooting at them because they cannot be destroyed.
Watch out for the boss' huge foot that aim players in groups.
Keep moving around when the red lasers are fired. You will instantly die if you stay still or in the laser's way.
The cannon, missile and laser pods can be destroyed from the boss body. Simply concentrate on shooting these parts (indicated with white black smoke and turn into reddish if they're about to destroy) instead of the main body to lower the boss' firepower.
Boss HUD Icon
Colossus is so far the largest boss in Counter-Strike Online, beating the Kraken size.