"Crackle."
The thunderbolt and flames in Merlin's hands combined in an instant. However, when he tried fusing the Wind-type spell, his spell fusion became unstable immediately, on the verge of collapse.
Merlin shook his head helplessly. It looked like he was still unable to find the critical point, and thus unable to fuse three spells for a long while now. If he was able to do so, the might of his spell fusion would rapidly flourish. At that point, even those peak Ninth-level Spell Casters who had fused two Spell Models would be no match for Merlin.
It was just that fusing three types of spells was too challenging. Merlin had even decisively used the Wind-type spell as the third spell to be fused. Wind-type spells would not clash with Fire-type and Thunder-type spells. Even so, it was of utmost difficulty to merge a Wind-type spell with the existing spell fusion.