Things the antichrist will do at about the time he rises to power or shortly thereafter

He receives a deathblow from some would he assassin. And to the amazement of the whole world he recovers from what would otherwise be a mortal wound. While it is purely conjectural, some think that he actually is dead by all standards and is revived directly by Satan. This belief is why some also believe he will acquire the full spirit of the god of this world (Satan) at that very point, and will be fully possessed of the Devil. Others tend to think that whether this is true or not, that the entire event serves in some way to mock or re-create the resurrection of Christ. Revelation 13:3

He changes the time and the seasons as we have known them throughout history. Some think that means he will end marking time by BC and AD, and start a new era marked by the advent of his own rule. Echoes of this can be heard in Hitler