Guardians of the Galaxy Vol. 3 was by far the darkest installment of the franchise, presenting one of the MCU's most brutal villains yet with the High Evolutionary. The Guardians films have always worked hard to thread a delicate needle, balancing the often traumatic "found family" trope with humor and pathos. While Chris Pratt's Star-Lord is ostensibly the main character, the heart and soul of the team has always been Rocket Raccoon, and the High Evolutionary actually has a lot to do with that.
Source:https://www.cbr.com/high-evolutionary-mcu-big-bad/