Pray like a mantis
Mantis has an incredibly cooky personality. However, seeing as how she was raised alone on Ego the Living Planet, she never had got the chance to learn how to interact with humans, let alone how to make use of her powers. So, upon joining the Guardians of the Galaxy, she realized that she needed to learn, and fast!
Sharp-eyed viewers will tell you what kind of fighting style she adopted. In fact, her name is a dead giveaway. In Avengers: Infinity War, you can see Mantis holding her hands like a praying mantis would while sneaking up on Thanos.