Drax is known as "The Destroyer" in the Gamora due to her ties with Thanos, but formed an alliance with the Guardians to track down Ronan instead.
While writer/director James Gunn helped turn Drax into a bit of a comedic character, he has traditionally been one of Marvel Comics' most powerful fighters, hence his title as Drax the Destroyer. The MCU also altered Drax was given a hatred for Thanos after Arthur's memories were erased, and he traveled the galaxy living up to his title, "The Destroyer." Without this origin for Drax, the MCU managed to create its own history for his name.
Drax's MCU origin and the birth of his "The Destroyer" name mirror the comics by having family tragedy still be the driving force for his actions. After Drax's wife and daughter were killed under the orders of Ronan the Acc, Drax began his quest to get revenge on the Kree zealot. During this time, he killed 22 individuals and was charged with five counts of grievous bodily harm, earning himself a reputation as one of the most deadly beings in the galaxy. These acts are what gave him the nickname "The Destroyer."
Even though Drax has kept his "The Destroyer" title in the MCU, the films have shied away from this side of him with each entry. He relishes the violence in Guardians of the Galaxy and is responsible for killing Korath in the third act, but Drax also loses to Ronan twice, even though he is the person he most wants to kill. Meanwhile, the opening of much less kill him, as he vowed to do at the end of Guardians of the Galaxy since Ronan worked for him.
With Drax slated to return in This could come through flashbacks or be part of the main story as the Guardians take on another cosmic threat. So far, the villain of Guardians of the Galaxy Vol. 3 is unknown, but Drax's strength could be needed to fight Adam Warlock, the High Evolutionary, or an entire alien invasion potentially. And if Drax survives the end of the trilogy, then future MCU movies could also be a chance to show him as "The Destroyer."
