the term antichrist is not useed for the one who performs miracles.
He is called the false prophet ,son of pedition,manof sin.He is also called the king of the north in Daniel.
But no where is that man called an antichrist.
No, that won't work. The word "antichrist" is made up of two Greek words in the NT manuscripts, 'anti' and 'Christos'. The Greek word 'anti' does not mean only 'against', but also 'in place of' or 'instead of'. And per John's definition later, it's ANYONE who denies Christ Jesus. Would that include Satan then?
YES! For Satan is the chief denier that Jesus is The Christ, the origin of that denial starting with the devil when he first coveted Christ's place at his original rebellion.
That's what John was pointing out in the first phrase of 1 John 2:18, the idea that they had already heard that antichrist should come. Our Lord Jesus in Matt.24 and Mark 13, Apostle Paul in 2 Thess.2, covered BOTH ideas, that of a coming singular antichrist, and the idea of many antichrists that follow the devil.
In Matt.24 Jesus covers first the 'many' that come in His name saying they are Christ, and then later a specific warning about 'a pseudo-Christ' ("false Christ" per the Greek) that's to come actually working great signs and miracles to deceive with.
In 2 Thess.2, Paul covers BOTH also, the first about the man of sin, a singular one coming to sit in the temple as God working those same signs and wonders to deceive with, while also later the subject of the "mystery of iniquity" (the antichrist's little helpers, i.e., the "many antichrists").
Even with the idea of John's "spirit of antichrist" there's no way to get around how that's pointing to the spirit of a singular antichrist which many receive.
Then, if one really wants more evidence about a singular antichrist that's to come, they can go read how the early Church fathers interpreted 1 John 2:18 in relation to the false one of Daniel 11, Matt.24:23-26, 2 Thess.2:3-4, and Rev.13:11-16.