Silvana

Silvana is one of the main characters of Season 2 of the Lucky Besties anime. She used to be evil, and was Arle's doppelganger. She was able to transform into (Unlucky*) Disharmony. She was also able to, by using negative energy or turning thoughts or words into negative energy, control Arle, making Arle into Unlucky Dissonance in Episode 2 of Season 2. However in Episode 2 of Season 2, Lucky Harmony was able to cleanse her heart, and Silvana was not able to take control of Arle or transform, and her powers are used for good. She has now befriended the girls and has a possible crush on Arle.

(*)
*The "Unlucky" before the Doppelganger's transformed forms is an unofficial naming, confirmed to be unofficial in Episode 2 or Season 2 when Lucky Harmony, now taken control of, introduces herself as Unlucky Dissonance.