You mean Jagers (Pronounced Yagers) from Pacific Rim.
My world has no Jagers, its not about humanity fighting the monsters, its about the ruins of humanity that gather around the various Kaiju for both protection and worship of the Kaiju. In exchange they take care of the Kaiju in the down-time between when they have to defend their territory form other Kaiju or the occasional "Arena" battle for additional resources.
So really its Kaiju fighting Kaiju with humanity just trying to survive, though some Humans can form a Psychic Bond with and Ride the Kaiju.