I haven’t enough time to make a Legend concept so I made this...
Overview: A serum that Tremendously increases the speed and strength of the user and considerably increases the user’s sensory responses in return for shutting down the part responsible for intelligent thinking. Thus, giving the user a animal-like state.
Effect: The user is forced into using his fists and the damage dealt is increased by 50% The user moves 50% faster and has gives the user threat vision like bloodhound’s ultimate. The effect lasts for 15s
(This is what it looks like.)