Without deviating from my opriginal question below, i am not asking for comparisons but clarity with the analogy below, as i am still unsatified with how far one can take plagiarism as in the context below of a comic super hero.
Thanks for the detailed reply, what about if for example we take superman and another comic writer creates another hero with similar characteristics like x-ray vision, super hearing, optical beams, faster than light, bullet proof, gets his energy from the sun had a red cape....etc, but had blonde hair or no hair at all. That would be blatant plagarism and I take it, it also is never acceptable???