Degenerate

Degenerate (変質者) or Shapeshifter (変質者) is a Unique Skill originally owned by Shizue Izawa. After consuming her, Rimuru inherited it from her. This Unique Skill was sacrificed by the Unique Skill "Wise One" in the process of evolving Rimuru into a Demon Lord to meet the requirements for receipt of the Harvest Festival gift and successfully attempt evolution into the Ultimate Skill, "Raphael."

Effects
Degenerate has two effects:
 * Synthesis (統合): Transform two differing targets into a single object. Can be used to merge Skills together, evolving them into new skills. More than one Skill can be acquired from the merging depending on the combination used.
 * Separation (分離): Release the properties inherent to the target and make it into a separate object. (The original object may disappear if it has no physical form).

Trivia

 * The kanji for Degenerate is usually a slang word used to describe Perverts or extreme Eccentrics which is where the pun comes from where Rimuru teases the spirit of Shizue inside him at a comedic panel of the manga at the end of Chapter 12. However, the meaning of "Degenerate" relating to this skill's abilities is a more literal interpretation of the meaning of the kanji: the word "henshitsu-sha" is formed of the kanji 変 (hen), meaning weird, and 者 (sha), meaning person, but 質 (shitsu) could mean nature (e.g "the sadistic nature of the demon") or qualities (e.g kindness is a fine quality in a human). From the former, the meaning of "pervert" is derived, however, using the latter this could be interpreted as something like "a person with strange qualities"; from this interpretation a meaning akin to "shapeshifter" is derived.