The hidden being had said that it would first harvest the Grimm Monsters and before targeting the humans, but that doesn't answer my question on why it chose the Grimm Monsters first.
It could have chosen the Humans first before choosing the Grimm Monster or both of them together, but it chose the Grimm Monsters first, and that created even more questions in my mind than before.
"PLANER SUPRESSION!" Hidden being said when I was struggling to find the answer to the question.
"Planer Supression?" I asked back; though I know what planner suppression is, I couldn't find the link between it, and it is choosing the Grimm Monsters over the humans first for the harvesting.
"SPAWNS OF ABOMINATIONS ARE NOT OF THIS WORLD, SO IS THE LITTLE SPIDER, THOUGH THERE IS GREAT DIFFERENCE BETWEEN THEM, THE WORLD WILL FAVOUR THE LITTLE SPIDER AND AID IT IN HARVESTATION OF SPAWNS OF ABOMINATION."