To address teammate debuff while in the gas, teammates could go up to Caustic and hold x or e (console or PC) to take a gas mask from him. It would appear near where you see your armor and helmet and it would have a health bar. The bar deterrioates after a certain amount of time spent in Caustic gas (yes this would apply to friendly and enemy gas) maybe 5-10 seconds. Then when it runs out they would have to go to their friendly Caustic to grab a new mask. In my opinion, this wouldn’t break the principles of the devs with regards to abilities affecting everyone equally, and it isn’t a “get out of jail free” card to be immune to gas for the whole game. There would be a cooldown on grabbing a mask from him so you can’t just run in to an enemy Caustic ult and stay next to your Caustic and spam the button to grab a new mask, and would still allow for your team to get some damaged on slowed enemies in the gas and leave the radius of the gas before they were affected.
An addition to his passive could also be made, where he holds charges of syringes which he can hold x or e, and with a short animation, inject his teammates to increase their time of immunity in the gas. Both of these additions would encourage communication between teammates. The syringe charges regenerate over time and it’s effect lasts only a certain amount of time from when Caustic inject them, unlike the masks which have an effect timer that counts down only while in gas.
