Sage

Extra Skill Sage (賢者, Kenja) is one of the first two Unique Skills obtained by Rimuru Tempest (the first being Predator). The Voice of the World granted him this skill during his death as Satoru Mikami.

His final thoughts of regret for remaining a virgin right till death allowed him to get this skill. The logic behind obtaining this skill specifically was the saying that a person becomes a wizard if they remain a virgin till they're 30.

Sage almost immediately evolved to Great Sage when Rimuru (Satoru) realized that since he was about to reach his 40s, he must be more superior than just a sage.