After hijacking the mind of an animal, he used the Sensory Hijack Metac to tune into their senses and see through their eyes. Then he sent the animals to look for specific cultivators for him.
His main targets are killing cultivators and the giant strength cultivators. So he looked out for giant warriors and cultivators wearing red robes.
When he found his targets, he froze their minds with the Mind Freeze Metac. That rendered them immobile and gave him time to reach them with his true body.
He had to meet them personally so that he could take their Core Metac. So the moment he meets them is the moment they will die.
And this was the case. As soon as he met the helpless target, he marked them with the Tracking Ability of Fenrir. Then he killed them.
Their death transformed the mark into a seal. From there, he pulled out their Core Metac and devoured it.
