>>57488
Generally speaking, it's better to design an original character as your board-tan than to adopt a pre-existing one. Since a board-tan will represent you in any potential OC it might inspire, it's better to establish yourself as a community that stands on its own, rather than creating confusion with known characters. If you use Kinnikuman or Tiger Mask, people might confuse you for an anime community and you'd draw in the wrong crowd.
Of course, inspiration from pre-existing characters is allowed. Just make sure your board-tan isn't a blatant ripoff of someone.