Reasons

When he got an idea, about how he had to understand how to use the skill first and couldn't use it right away, Clyde decided to immediately drop the thought of the fire serpent.

If indeed what he thought was true, then Clyde could only use that skill when he left this Fortress. He had to look back at his Character Information and see the Skill's explanation.

Knowing that he couldn't do that now, Clyde only focused on using the skills he could use now. Clyde can only create fire with the sword, so he tries to combine his fire power with the sword's fire power.

It turned out, the results that happened exceeded his expectations.

*BWOOOSSHHH!!!*

Clyde raised the red bladed sword above his head, flowing Mana along with his [Skill: Burning Hand]. Then a fire vortex with a diameter of ten meters was created almost instantly.