They know what might hurt you most
They find out your weakest spots and then they hit them to make you hurt. Do not let a toxic person in. Otherwise you will feel betrayed and hurt. Do not tell them too much about your worries and problems since toxic people will only make everything worse. Be careful and try to be neutral in your answers to what is going on in your life.
They can be extremely nice
Whatever comes in excess is wrong. Even if you are extremely nice, it can bring harm. Toxic people can easily trick you into thinking that they adore and worship you. They do this when they know they can benefit from the situation in one way or another. They are generous with favors and compliments. However, if all those nice actions and words come from a toxic person, you should not trust them too much. Be realistic and admit that it may take ages for a toxic person to be genuine and sincere.