I actually have two interpretations from this.

Interpretation 1:
From what I had picked up from this song mostly, is the sheer fact that the protagonist was maybe taken over by his obsession/possessiveness of the person he loves. In The Nameless you can tell he's pissed off and getting impatient with his lover, as she's most likely refusing to love him. Maybe he even thinks she's lying which brings this verse to attention; "Confession (I won't tell you twice)". At this point he's engulfed with some kind of pent up rage he had from her, simply not admitting to something that isn't even true. He's just hurting her now maybe thinking she deserves it, because she isn't in love with him. So all these different emotions he had building up may have caused the snap in, The Virus of Life. The lyrics are mostly self explanatory if you think deep enough about them. I think the protagonist finally spiraled out of control in this. Fully corrupted by the desire to have his lover not only in one way but in a sexual way as well, which may have driven to him raping her. In the sense of murder, the vibe of the song itself just gives off a murderer vibe. The lyrics kind of hint to death too, It could be a "If I can't have you nobody can", type thing which would make sense because of his possessiveness.

Interpretation 2:
Only listening to this song alone and not any of the other songs it ties into like; Vermilion, Vermilion PT.2, The Nameless, and Danger-Keep Away, this song could have been a cry for help or something more, due to mental disorders or illnesses. Think about it as your in the shoes of whoever may be slowly getting consumed by a certain mental illness/disorder they have or multiple, and the vocals of this song is the voice inside of your head or the demon of that illness/disorder slowly creeping up on you ready to consume you at any moment, like the protagonist. I know this may have been a lot to read but I had a lot to say (and I still have more to say but I don't want to bore the people who may be reading this out ). By the way, hello to the maggots listening in 2021.