Summonine

Summonine is the main antagonist of Summonoid, who wants to summonoidise Summonia into Summonoidia.

Story
Summonine was the first summonoid to be made. Shortly after being made, she wanted to summonoidise Summonia into Summonoidia. She starts by transforming villages into summonoid cities, and their inhabitants into summonoids. Fortunately, Summonine has not summonoidised everything and everyone yet.

11 years after her creation, 2 enemy villagers, known as Summonine's assistants, or SA's for short, start helping her in her plan to summonoidise Summonia into Summonoidia.

In the "Serendipity Breaks Free" ending, Summonine, along with SA #1, simply have a change of heart and decide to help bring Summonoidia back to Summonia.

In the "Pania's Special Power" ending, Summonine and Serendipity team up to do a special move, which summonoidises everyone but Pania, who manages to bring everyone back to normal. In this ending, Summonine and SA #1 have a change of heart, but apologise before helping bring Summonoidia back to Summonia.

In the Ambivalence Ending, Summonine and Serendipity try to do their special move, but the villagers are unaffected, since Serendipity gave them protection items before teaming up with Summonine, and they put them on. Summonine, along with SA #1, have a change of heart and start to become more expressive as Yumiko sings her song, and at some point, decides to sing along. As the song goes on, Summonine starts to help bring the summonoidised villages and villagers back to normal.