MarsSeed [1] filed a deletion request for ninka [2]: Tool's developer was the package owner. They disowned this package upon small maintenance request. Project abandoned, source hasn't been updated in 6 years. Only 1 other package from this same developer was using this package. Safe to delete, guess owner/creator discontinued these projects.
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/ninka/
