Board Thread:Warhammer 40k General Discussion/@comment-68.32.121.238-20141103170325/@comment-6078851-20141104152623

as mentioned emps thought horus was still redeemable. despite the numerous atrocities horus was reported to have perpetrated emps had difficulty in believing what he heard, what with horus being his no.1 son and all, and so tried to bring horus back from the darkside during their duel.

not until horus psychically flayed someone in front of emps did emps finally credit the reports of horus' actions, and then realised that horus was beyond redemption. except by that point emps himself was wounded beyond recovery.

a large part of the issue was indeed due to emps' ego. i imagine he thought something like "of course horus can be saved... i created him." emps needed to believe this because otherwise it meant that magnus was right (and emps doesn't like to be told he's wrong, which he was) and emps had to take responsibility for ignoring that warning and the subsequent destruction of prospero.