There are some scientists that wants to make human look unbridled and untrustworthy. They make a bullet with weird mixture that makes humans aggressive and bloodthirsty.
Human [name] was spending some time with her co-workers when she feels a little pain in her neck, she blackout. When she wake up she was bonded by her friends and not her blood was on the floor, her and her co-worker. -- Anon Guest
Like all problems in the known universe, this one started with ambition mixed well with hatred and xenophobia. Those three have forever been a toxic combination and will ever be so. Beware them, no matter the pretty cover stories they wrap around themselves.
Nevermind the name of the instigator. People like those are best forgotten, anyway. They had their justifications, they always do. The Humans were everywhere. They were outnumbering civilised folks. They had a barbaric faith. They were barbarians. They were toxic. They had horrific traditions and history. They smelled bad. Take your pick. They were always and ever will be pretty words surrounding a core of unreasoning hatred.
It culminated in a tiny dart no bigger than a carob seed. The toxin within was as clear as the soluble material that was its casing. It was a work of art. It was a work of evil. They called it 'berserk', after the raw savagery that some Humans were known to be capable of. What they had done was find the perfect formula to trigger any given Human into their deepest, most brutal fight-or-flight instincts, and ensure that the switch was flipped to 'fight'. This, they reasoned, would highlight exactly what the Humans could do to the Alliance. They were not wrong.