Cecil is possessed by a linguophage - a word-eater.
The linguophage was born out of all of the unsaid words and enforced silences in Night Vale (“If you see something, say nothing…”). Both an addict and a devourer of spoken language, the linguophage was drawn to a young Cecil, a bright and verbose mind; “Cassette” describes his haunting and possession by the linguophage. It now lives in his mind like a symbiote, enhancing his lyrical and mellifluous voice, giving him the power to see and speak what the rest of Night Vale cannot and feeding off his forbidden words. Thus Cecil is literally the Voice of Night Vale.
Everyone that Cecil cares about will never die. Everyone in Night Vale
have varying degrees of immortality because of how much Cecil cares
about the town. The Apache Tracker died because Cecil didn’t care about
him at all.
Cecil is mildly clairvoyant. Sometimes he will just know something
without anyone ever telling him about it. He is unaware of this ability
though. He always assumes that an intern reported the information to him
and he just forgot about it.
Cecil’s radio show can be heard just about anywhere if the right things are set to the right frequency. It can be heard on radios, microwaves, tamagotchi devices, pencil sharpeners, and comatose people all over the world.
Cecil’s voice can be hypnotic, literally hypnotic. Sometimes he has to be careful about what he says to people because if he isn’t people will start sending each other boxes of excrement and doing inappropriate things in the street. Which is the real reason he doesn’t use curse words on air.
When a prophesied Voice of Night Vale becomes an intern at NVCR, they start existing as a fact of Night Vale from the beginning of time until the end of the universe. They are not aware of this, which can lead to strange memory problems. They also cannot be killed - the universe will go to great lengths to make sure they are not harmed, even deleting an entire third world war in the 80’s from existence.
Leaving their role, even temporarily, can damage the spacetime continuum - this is why getting a vacation is so hard. If you retire and Station Management already has a willing replacement lined up, spacetime usually repairs itself…eventually…but there’s no way to tell what sort of horrible stuff will happen to you. This also has strange side effects on the Voice’s family and loved ones. Earl’s time weirdness, the disappearance of Cecil’s mom and brother, Steve’s arrows in the sky and Carlos being missing from the outside world for decades are all a result of their lives being directly intertwined with the Voice of Night Vale.
Cecil had no idea why there seemed to be an invisible studio audience in his broadcast on the condos (after all, disembodied cheering usually only occurs during lacrosse games, accompanying street performers, and that one time when you spilled your coffee) but they didn’t seem particularly malicious so he just went with it.
Cecil doesn’t experience time in a linear way as other people do. This is why fell in love with Carlos instantly - he simply felt their future relationship. This is also how he knows about things as they are happening sometimes, and even reports on future events.
Whenever Cecil swears, your standard bleep of censorship comes out instead of swear words. It got to the point that that noise has become a swear word, so even though it happens, his swearing is censored with silence by technicians when he’s on air.