Board Thread:Skyrim/@comment-11618741-20150726035340/@comment-6881629-20150726115648

Theres a section on the quest page about completing the quest without killing Paarthurnax (basically just skip the to the end with setstage). The UESP way does sound like it would be a full reset back to the Blades ignoring you.

Theres also [http://www.nexusmods.com/skyrim/mods/18465/? The Paarthurnax Dilemma] or [http://www.nexusmods.com/skyrim/mods/63900/? Paarthurnax Bypass] mods (which is actually voised).