"Amon was twenty-two years old when he became king, and he reigned in Jerusalem two years. He did what was evil in the Lord’s sight, just as his father, Manasseh, had done. He worshiped and sacrificed to all the idols his father had made. But unlike his father, he did not humble himself before the Lord. Instead, Amon sinned even more. Then Amon’s own officials conspired against him and assassinated him in his palace." (2 Chronicles 33.21-24 NLT)

Manasseh sinned against the Lord, but he repented and turned to God. (2 Kings 21 did not record Manasseh's repentance, in contrast to 2 Chronicles 33.1-20) The people around Manasseh - his team - obeyed him and committed their lives to the Lord too.

So when Manasseh's son did not follow the Lord, the people that remained from Manasseh's reign intervened. They wanted the kingdom that Manasseh left behind to remain following the Lord.

But the story did not end well for Manasseh's team. They obviously upset the political and financial power who benefited from Amon's sins. So they killed Manasseh's team.

This team probably knew what was coming for them, but they were committed to cleanse the throne from evil as best they can.

And they did not die in vain.

"But the people of the land killed all those who had conspired against King Amon, and they made his son Josiah the next king." (2 Chronicles 33.25 NLT)

Josiah eventually brought the kingdom back to worship the Lord. Josiah's story has been told many times but we still do not know the names of Manasseh's team.

Note: I do not have any fact to support this story. It is my speculation.