Knull says that the fools had sent him back to his void, or abyss.
Okay no biggie. Knull the blade, and the severed Celestial's head are banished to the void. Knull then begins tempering that same blade.
Abhi I once did the same thing while reading the bible. Jesus was asked by the demons that possessed Legion to send them into the pigs that were close by instead of out in the world without a host, and I thought that the demons were asking Jesus to allow them to have sex with them.... Serious story that. All the same I asked someone about it and the truth was revealed unto me.
Just ask someone else what they think, and if they go with your theory then there's a good chance that you both may be lost. LOL. Kiddin bro.