However nations and multitudes are lead by a leader. The antichrist in Revelation would very well be one man.
Revelation 13:1-5
And I saw a beast coming up out of the sea, having ten horns and seven heads, and on his horns were ten diadems, and on his heads were blasphemous names. 2 And the beast which I saw was like a leopard, and his feet were like those of a bear, and his mouth like the mouth of a lion. And the dragon gave him his power and his throne and great authority. 3 And I saw one of his heads as if it had been slain, and his fatal wound was healed. And the whole earth was amazed and followed after the beast; 4 and they worshiped the dragon, because he gave his authority to the beast; and they worshiped the beast, saying, "Who is like the beast, and who is able to wage war with him?" 5 And there was given to him a mouth speaking arrogant words and blasphemies; and authority to act for forty-two months was given to him. NAS
People not nations speak "arrogant words and blasphemies".