The Praying Mantis
Mantis is probably the cockiest character in the Guardians. She was left to fend for herself on Ego’s planet, so her knowledge of fighting, while there, is limited, to say the least. When she decided to join forces with the Guardians, she took it upon herself to learn to fight on the fly—or on the mantis, rather. Sorry, that was bad.
The more astute viewers out there will point out Mantis’ incredibly unique fighting style, which is probably derived from her name, Mantis. You can also see her adapt her fighting style when she sneaks up on the big purple bad guy in Avengers: Infinity War.