Attacking the Lair of Nightmare Dragon Clan

At the same time, a black Divine Dragon surrounded Levi and enveloped him.

Thunder Dragon Flash!

The black lightning streaked across the mountain. He flew out quickly. Wherever he passed, the black lightning would remain and corrode the rock layers.

"Not bad."

Levi opened his proficiency panel.

Levi-

[Thunder Dragon Flash: Level 11 (Maximum). Special Effect: Thunder Reverberation.]

[Thunder Dog: Level 11 (Maximum). Special Effect: Thunder Reverberation.]

...

[Thunder Reverberation: Your thunder spell will have a special effect. It can be attached to the surface of the target and cause continuous damage. The duration is closely related to the Proficiency of the spell and the amount of spiritual force.]

"So that's how it is. These special thunder spells are equivalent to adding a special effect to ordinary thunder spells. No wonder their power is generally better," Levi muttered.