Warning! Spoilers ahead for Eternals #3
Marvel Comics' Eternals redefine how superpowers work when it comes to their immortal race in the Marvel Universe. Rather than being like the X-Men who are all born with unique powers and abilities from one another, every Eternal essentially has the same power set and can do the same things if they so choose. However, each Eternal ends up specializing in certain powers over others, so much so that said powers end up defining their very personalities, as seen in the first three issues of their new series from writer Kieron Gillen with art by Esad Ribić.
Created by the cosmic Celestials, every Eternal technically has the same powers and abilities: "All Eternals are capable of super strength, teleportation, telepathy, telekinesis, matter manipulation, flight through levitation, creating illusions, and the ability to shoot cosmic rays out of their eyes and hands". However, what makes the Eternals so unique is that they end up honing in on only a couple of these abilities that they'll use for the majority of their immortal lives, so much so that it's possible that they were pre-destined by the Celestials to specialize in these powers and build entire personalities around them.
Marvel's new Eternals series has done a great job in depicting his concept, providing a core metaphor for each Eternal that defines not just who they are, but what they can do as well. Ikaris is an arrow. Not only is he direct and headstrong in his approach to situations, but he chooses to fly, make use of his super strength, and fires cosmic rays from his eyes. Alternatively, Druig is a snake who seeks to influence scenarios and others in his favor, making great use of mind control to get what he wants. Phastos is a forge and hammer, using matter manipulation to build all sorts of creations. Sersi is complicated, while Thena is a book and blade (the list goes on). As a result, it's no wonder the Eternals were confused for gods by early humans.
All that being said, one might wonder if these chosen powers by the Eternals were actually a choice at all. Were they pre-destined to choose the powers they did? The Eternals were a planed species manufactured for a specific function after all, made to battle and eradicate the Deviants, a secondary creation of the Celestials seen as abhorrent. It's possible that the Celestials wanted each of the Eternals to have specific powers and functions to order to serve their original purpose, while for some reason allowing them to believe they had a choice in the matter.
While the Eternals are no longer ruled by the whims of the Celestials, their functions and original drives are still inherent within them, almost like instincts. As such, it's possible that their powers end up defining them so much that they actually can't deviate from the powers they originally"chose". The powers they wield are ones they're eternally stuck with in Marvel Comics, which would certainly be a fairly wild concept when it comes to their existence and creation in the Marvel Universe.