Behemoths of Suvysah (kinda a pacific rim copy)

On this distant planet in a galaxy far away prospering civilizations inhabit the world along with many wonderful creatures but that all changed when the Appearing happened. A few months ago mysterious giant portals appeared which when observed look like giant mirrors but they couldn't be more different. One portal which appeared next to Zhayl began shifting and before the eyes of hundreds of thousands people a giant beast appeared. This beast wasted no time and destroyed the city in a matter of hours but luckily messages went out to other kingdoms and cities so they had some time to prepare. But that did not stop these massive beast that appeared from the portals as they soon brought havoc across the whole world. Finally after 6 of these beasts wrecked the world for a few weeks the combined forces of the world took them out. Now a few months have passed without any more of these massive beasts now known as Behemots appearing. Some say there is a super secret project to battle the Behemoths. (If you have any ideas or recommendations be sure to let me know)