Characters with bigger hitbox should have more health

@makaramus 
Caustic is fine for most part - he is a denial legend and all he needs is simple tweaks to his hitbox (so it reflex his body, not his clothes) and make Nox Gas a "poison" - once you get affected it lingers on you. And his gas to not slow allies, let's say he provides teammates with small breathing device when he is nearby. Gas should also slow a bit more - it's too easy for some to just slide through it (seems slow doesn't affect the sliding speed).