This spy is far from helplessness. For he can absorb a monster's ability and use it for his own needs.
A whily spy greedy for power, hunts down every monster he can find and absorb to increas his own power.
Which is being able to absord monsters abilities.
He is mentaly quick for a spy which gives him quick thinking in fights and being able out witing any monster as he gain more power.
This is a gess. what ever monster ability he absorb, he also absorbs the monster's Phicical weaknesses.