For caustic I'd probably give him a respawning amount of barrels that is comparable to Wattson Pylons. Personally just think he could use more barrels.
That or maybe a movement buff while inside the gas where he gets like 75% of the buff Octane gets but only while in Gas
or maybe he gets a damage reduction while in the gas.
Or perhaps have his gas heal him over time at the speed that Watson/octanes passive regeneration works but he has to be in active gas for the regeneration and it's only for white health like he's grown such an affinity for his poison that it heals him.
These are some ideas that could be balanced to work. Keyword not all of them applied to him at once tho that'd be broken
Imagine nerfing a legend ability, then complaining about static barrels you can destroy by shooting the bottom of them, or just walking around them
