There were many reasons. His body was currently bearing an extremely high load as he flew backward, though his brain and thoughts remained clear thanks to Future Sight. However, the Magic Power within his body was still rapidly oscillating and in a highly unstable state. Under these conditions, not to mention a Level 2 proficiency skill, even Level 3 or higher skills ran the risk of failure.
Another reason lay with his opponent. The Spiritual Power Talent of Demons was indeed relatively poor, and goblins were not a race known for excelling in this area. But it had to be understood that mental states were not set in stone. The exact same Spell involving the spiritual Domain would have drastically different effects when cast on a drowsy person who had been working exhaustively for days without rest, compared to someone energetic and in a state of extreme excitement.
