model o (mega man)
Biometal Model O is a secret biometal usable in the post-game for Mega Man ZX. It's design is a direct copy of Omega from the Mega Man Zero series. There are no depictions of a solo transformation using Model O, as every transformation in ZX by the protagonist is done by combining with Model X. This tag is to identify the biometal construct itself.
Vent or Aile from Mega Man ZX may also use this form, combined with Model X to transform into Model OX.