When Yinn confirmed that there was no more movement, she moved in along with her Fortress Golem and checked the corpses. Without any hesitation, she used the Fortress Golem's scanner to find the power cores and once she did, The manipulator swooped down the valley to pluck them out from any of the mess they were in.
As long as they do not have their cores with them, it should be impossible to revive back again. And also, those cores retrieved can also be recycled as Yinn installed them into her fortress golem and found that it boosted her processing by a significant amount.
This way, she would be able to do even more complicated reality blending techniques that might even rival Jin's dungeon creation concept. When it was all done, she placed several bombs at various locations before leaving the valley so that those broken Mecha Dragons would never appear once more.