The last one because it make the most sense
Answer: I think its right, Diane solves problems patently and she can work with patients nicely but the Number Devil helps people solve problems in math and he gets upset easily with the person he is working with.
Explanation: How is you day?
Grendel is a brutal and strong man-eating demon who loves violence specially fighting, killing and devouring humans. He seems to be a half-human half-beast, having human feelings with superhuman strength that kills people without hesitation. His soul is filled with resentment and jealousy for the humans for it seems to Grendel God has blessed them and not monsters like him.