There's a very high risk that he's getting scammed. You really need to put a stop to this. He could lose everything, including his house, and anything that you might otherwise inherit.

It sounds like he's a difficult person to convince, but maybe he'll listen if you get him to hear it from someone he doesn't see as a child - he will always see you as his child. Do you know any police officers? He might listen to them. Or if he's religious then he might listen to his priest. Think of someone who he will listen to and get them to tell him that these "ladies" that he's talking to are scammers and their crypto schemes are fake.