Strangely enough, this sentence-prophecy of “you will see”, seems to refer with equal strength to the secondary sentence (don’t doubt that you will see them in person) and to the condition of each of them personally.
The secondary or intervening sentence seems an indirect question, yet it is a reference, you will see all who sinned, don’t doubt, not one will be missing. This “not one” is the “if” at the opening of a sentence which is analyzed further to the just condition of all sinners. This way the future of Orestes is made concrete. By focusing so boldly to the personal knowledge of sin in each and every sinner, they make him feel already in hell.
Ἀσεβῶν is a participle (not respecting a stranger). Sin against God is direct (ἤλιτεν Θεὸν) and is indirectly against God again: ἤλιτεν Θεὸν by ξένον τινὰ ἀσεβῶν (the same for the parents).
Εὐσέβεια (well knowing and respecting) a man (a stranger or your parents) is understanding his coming from God. When Odysseus wakes up naked at Phaeacians’ shore, he wonders, “Are they hospitable? Does their soul have the face of God?” (ζ 121). The opposite is ἀσέβεια, which is the condition of hell.
I still do not understand how "ei" fits into the translation. Would You translate it," If any other offended either god or some stranger, acting profanely, or beloved parents, each having the things deserving of justice, you will see (him)." I am having trouble fitting the conditional particle into the sentence. It seems like "ei tis" should be "ostis"
Try to imagine it spoken. “You will see if any other, etc., - you will see how he has what he deserves.” Maybe if you repeat “you will see” 2 times you will achieve a more natural rendering in English.
" you will see also whether anyone else offended either god or some stranger, having acted profanely against beloved parents..."
This translation seems to impart that there is an alternative to the statement when there is not i.e. "whether anyone else offended (or did not offend.) I thought about this being an indirect question also, but this translation did not seem to work. They cannot be used interchangeably because "if" introduces a conditional clause while "whether" introduces and indirect question.