Tooth Decay found out that after Nephalor called out a name, the other players in the team became marked in red, indicating that he could steal their skills at that time.
So, he tried to steal from a Priest, still harboring a glimmer of hope in his heart, expecting the situation might change.
However, the result was the same, he only managed to steal a skill called "Holy Fire," which dealt a whopping 80 points of damage!
Priests do have offensive skills, but the damage of these skills isn't very high. Even if a Priest invests in all the talents that increase Holy Damage, their offensive capabilities would at most, be around sixty percent of a Mage's.
The "Holy Fire" that Tooth Decay stole, as a Mage, he had no Holy Series talent enhancements of his own, just the raw damage of the skill itself.
Additionally, considering Nephalor was a powerful fire-breathing dragon with extremely high magical resistance to fire, it made sense why the damage was only 80 points.