People who are inherently bad often have these eight characteristics:

First, they like to pry into your privacy but never reveal their own. Because information imbalance equals power, if they know your details, they can manipulate you at critical moments.
Second, they embarrass you in public under the guise of "doing it for your own good," especially when others are around. They seem kind but are actually roasting you over an open fire.
Third, they bow to the strong and look down on the weak. This is the clearest test of character. Essentially, they have no principles; only interests and calculations.
Fourth, they excel at creating conflicts and sowing discord. Today, they gossip about others to you; tomorrow, they talk behind your back. They appear friendly on the surface but secretly make everyone suspicious of each other.
Fifth, they never admit mistakes and always shift blame. When problems arise, they look for scapegoats and even craft logical excuses to clear themselves, sometimes truly seeing themselves as victims.
Sixth, they are good at pretending to be victims to gain sympathy. They tell compelling stories, portray themselves as the most pitiful, and use tears and grievances to manipulate you—this is a high-level form of control.
Seventh, they habitually drain others' emotions. They see others' value but when that value is unrelated to them, they can't stand to see others succeed. If you become worse or depressed, they feel psychologically balanced.
Eighth, they turn hostile and forget kindness, repaying favors with betrayal. They forget your help ten times but remember one rejection forever. Once you lose your usefulness, they smear your reputation.
Sharing these isn't to make you suspicious or paranoid but to remind you to stay alert. Truly kind and broad-minded people won't resort to these tactics.
When you notice these traits in someone, don't hesitate—stay away promptly. Your kindness and time are precious; don't waste them on unworthy people. Staying away from toxic individuals is the best way to take care of yourself.