"Pylades (for indeed I consider you, foremost among men, loyal and kind and a host to me) ..."
The two adjectives πιστὸν and φίλον, joined by καὶ, are masculine singular accusative to modify σε. Finally, the noun ξένον is added by means of the postpositive conjunction τε. The γὰρ seems to function to make the phrase parenthetical, subordinate to the main thought which follows in lines 84-85 ("Pylades, ..., you were the only one of those close to me who respected this poor Orestes ...").