Re: Salvation for Nephilim. I think there may be an error with this comment: “Jesus had to become all man to save mankind. There’s no Biblical indication that fallen angels can be saved by the blood of Jesus.”
There’s no specific indication for angels but there is a general indication for all things on Earth or in Heaven.
“For God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.” (Colossians 1:19-20)
The context of my answer was the potential for Nephilim to be saved. Do you interpret this verse to mean that Jesus may have died for the sins of fallen angels as well as for mankind? Jude 1:6 tells us that they’re bound with everlasting chains for judgment . Can they claim Colossians 1:19-20 and be freed?
John 16:11 says that because of the Lord’s death the Prince of this world (Satan) now stands condemned. In Rev. 12:7-12, the Dragon (Satan) and his angels are finally cast out of heaven for good and heaven rejoices. I view this as the reconciliation of things in heaven to God.