EDIT: Just to clarify: Nerfing the card so the gas no longer follows you around still allows it to be super-powerful (it literally almost insta-kills commons on no hope WITHOUT CARDS BUFFING THE DAMAGE). It just does not allow you to skip the game altogether!
Long story short. When activated it releases lethal gas wherever you go for about 7-10 seconds. It deals weakspot damage, meaning it scales with such cards but more importantly it does fire damage which means frikkin' pyro doubles the damage and heals you.
This means that by merely investing 2 cards into e.t5 you can literally kill every last common (except charred) you pass without even needing to interact with theem. Couple this with speed cards and you can annihilate swathes of ridden while instantly filling your health bar with temporary health and running all the way to home base.
Please, for all that is good: Make e.t5 only release on the spot of activation, and remove the fire damage attribute from it.
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