Somewhere in Bermudonia triangle there is an island called Bermudia (damn I am original). Time is unknown but it is for sure way back then meteor stroked with specific metal material. Its particles were spread across the island. Creatures of this island were hit by it and so they mutated. Gravity was affected aswell, so the air. Some things became much bigger, like insects. Unknown metal integrated into their DNA. It affected their bone structure. It is visible everywhere. Every living creature started to evolve into smarter being and realized that this material gives power and with power comes anger. Weapons became part of evolution and so the war. Sides split and some exceptional creatures took actions either to defend their lands, others unfortunately wanted more power and more conquered land with precious material.