The relative pronoun ὅς strengthened with the intensive particle περ creates ὅσπερ: 'the very one who.' Often it's indistinguishable from simple ὅς, but the περ adds emphasis or precision. It appears after adjectives of resemblance: 'the same things as' or 'similar to what.' Homer uses it: 'the very man who struck' (ὅς ῥ᾽ ἔβαλέν περ). The oblique cases sometimes borrow from the article (τόπερ), especially in Ionic and poetic texts. The construction emphasizes identity or exact correspondence.