You get 2,000 cookies for this, that's it! It's very hard to get legit solo. Maybe they thought everyone would use a friend idk..
Ichiban poison is lack luster. I tested it over multiple matches and... stamina percent and avoiding the green doesn't seem to matter. I tested staying out of the gas and not running so my stamina stayed max, somehow I lost against a guy in a full green cloud of poison, not once but wait there's more. This took place over 10 mins so I don't have a clip.
ANYWAY here's the achievement caught in a clip.