I'm building a new character whose powers come from a "cyber skin implant" that is pretty natural to her since it's now part of her body, giving her 12 Stamina without Enhanced Trait.
Her cyber skin also makes her highly resistant, and being PL 11 I don't want to invest more into Protection or Dodge Roll, giving her Impervious Toughness 14.
Now, I have been looking at examples, and unlike Strength, it seems that Impervious modifiers are always given to either Protection or Enhanced Stamina (Like in the Paragon example on Hero's Handbook, which makes me think, since his Impervious Rank is more than his enhanced stamina).
All in all, is it possible to use this effect as it is?