The poor butler, before he could even reach the peak of his self-righteous rumble, had been suspended mid-air, unable to breathe.
There were quite a few things that didn't make sense from what he said, because as far as Eric knew he was the fiancée this guy was talking about, but he clearly didn't know him.
Secondly, where did this guy find the authority and courage to question the Princess, and her guests?
This butler was clearly delusional, and he had no intention of bothering with him much, for that reason he decided to give him a painless death.
The poor butler couldn't believe his luck, as he was slowly losing his breath and light, the tunnel became pitch black, and his soul left his body.
Eric could tell that the guards to the Princess room were eager to tell him something, or even act against him, but before they could say a thing the butler had disappeared.