Super Emo Charcoal or Angsty Blood Red
The timeless ether of the cosmos. So …. O?
Mischief, Tuna Mayo Onigiri
People foiling his mischief, people eating his Onigiri
Shoyu is the latest incarnation of the magical otaku spirit egg, which was introduced in Season 4. He was hatched by the congoers, who channeled their Otaku Spirit Energy into picking the Yandere Demon Turtle as the new convention mascot.
Before Shio and Kosho, he had 7 previous owners, which Shio and Kosho, along with the congoers, had to defeat the following year. Shoyu is a mysterious ageless creature that will continue finding magical owners long after Shio and Kosho have conquered the world. (Because they totally will, right?)