I responded to someone who said “Antichrist” isn’t in the bible by quoting it from said book. So they are ill-informed.

GGP didn’t say “Antichrist” wasn’t in the bible. They said that antichrist “as a figure” wasn’t in the bible. Even the Wikipedia article on Antichrist will give you a rich overview of this discussion and general scholarly agreement that that word as used in the bible does not reference a specific figure.

There is quite a lot of nuance here. You can’t just keyword search.

Many (most?) of the characters in the Bible are mythological…

Even if some are rooted in some real person, the stories about them etc. cannot be considered accurate historical accounts.