Zero

Zero was built by SPEKTRE (Special Planetary Enforcement Kaiju Threat Response) - the first of a new generation of Colossi built to defend the planet against the kaiju threat. Zero was named after their chief scientist Dr. Zeron, who had his own brain hardwired into the construct in an attempt to expand his intellect. The experiment worked - but at the cost of his sanity. 

Obsessed with stockpiling the Ichor for his experiments, Zero went missing for a few days. When he returned he had modified his body, arming himself with weaponry and hyper-advanced technology - and filled with rage...