The Tesseract - although he refers to himself instead as "The Will of the Universe".
He reveals to Masayoshi that the word "Flamwenco" has a 0.000002% chance of granting a wish, and that because of it, the universe has kept sending him new and exciting enemies for him to fight. After Samurai Flamenco talks with him and is briefly reunited with his Grandpa, the Tesseract accepts his request and stops sending him enemies.
It is also revealed that Flamwenco is the reason everything is named "Flamenco". It is a homonym, and the Tesseract compares it to how the Australian town Eromanga has an extremely different meaning for Masayoshi.