One major way to know if you’re dealing with an energy vampire:
They start problems then play victim. They’ve managed to provoke you/push your buttons and when you respond they suddenly go quiet. May even gaslight you and act like you’re the aggressor

When they do this, a energetic cord has now been formed between you two. The more angry/emotional they’ve gotten you, the stronger the cord. They can now use this cord to drain your energy. As you become exhausted, you’ll notice they appear to feel fine

Please take heed because a lot of people fall victim to this without knowing. The more upset you get, the more they feed. And the more they gaslight, the more you defend yourself and the more they feed.

The only way to “win” in these situations is to literally not respond and not pay them any mind. Which can be difficult because it’s a natural instinct to want to react or defend yourself. That’s why identifying your triggers and disconnecting them is important