H0R0: tell that to whoever runs the site. They can't be arsed to set up a tag for Mysterious Heroine XX, so I doubt we'll get a separate tag for Skadi.
Skadi should have her own tag, using Scathach tag is like using Rin Tosaka tag for Ereshkigal or Ishtar or like using Sakura Matou tag for BB or Meltlilith or Passionlip.