Warning: SPOILERS for Eternals below.

The ending of Eternals may have made Sersi the MCU's new most powerful hero. Eternals on the whole radically shifted the MCU's previous boundaries, introducing the Celestials explicitly for the first time and revealing that Earth has had far mightier heroes than the Avengers for much, much longer. The film shifted other Marvel Studios boundaries as well, featuring a diverse cast that also includes the MCU's first superhero who is deaf and openly gay heroes.

Sersi (Gemma Chan) is the Eternal that Ajak (Salma Hayek) chooses to take leadership of the team after the latter's death, due to her connection to and love of humanity. Sersi's powers include immortality and super-durability like the other Eternals, and her particular skill is transmutation. She can transform matter at a touch, like turning an incoming bus into rose petals, for example. Sersi elaborates at one point in the film that she cannot, however, transmute sentient beings, but this changes after she assumes leadership from Ajak. Sersi is able to change a Deviant into a tree, which helps set up the Eternals' final plan to have her turn the Celestial Tiamut into marble.

Related: Marvel's Eternals Powers Explained: What Each Team Member Can Do

Sersi's monumental achievement of overpowering a Celestial, one of the most omnipotent types of beings in the Marvel universe, flags her as a potential candidate for the MCU's most powerful hero. However, it's not Sersi alone who accomplishes the feat; she's able to boost her powers significantly by tapping into the energy of all the other Eternals through Phastos's Uni-Mind invention and harnessing the cosmic energy generated by the Emergence to transmute Tiamat. Thus, it's not really Sersi who is the MCU's new top dog, but rather the Eternals as a unit.

The MCU bosts many absurdly powerful characters. There are the likes of Thor and Hulk, who had rather modest Phase 1 debuts but have had their true potential revealed more over time. Doctor Strange has also been imbued with great power since his introduction, with What If...? taking the full implications of his abilities to a whole new level. WandaVision seemed to confirm Scarlet Witch as the MCU's most powerful character with the force of her hex, and last but certainly not least, there's Captain Marvel. Thanks to her exposure to the Tesseract, she has strength and abilities on a cosmic level no other Avenger seems to have matched, going blow-for-blow with Thanos in Avengers: Endgame like it was no problem. Compared to some of these heavy hitters, Sersi is certainly an equal due to her status as an Eternal, but it might be a stretch to name her the unequivocal winner.

What sets Sersi apart is the power available to her through the other Eternals. Thanks to the sphere she inherits from Ajak, Sersi taps into her abilities to transmute a living creature for the first time. With all the Eternals linked by the Uni-Mind, she turns a Celestial to stone. During the Eternals climax, Sersi is the most powerful hero in the MCU, but she herself admits afterward that once they unlink, her power starts to return to normal levels. While the likes of Scarlet Witch and Captain Marvel are more consistently omnipotent, Sersi can't access the full range of her power whenever she wants; she needs the rest of the Eternals to do that. This does, however, imply that the Eternals together are the most powerful MCU character when they are all linked as the Uni-Mind. Thus, while Eternals does introduce Sersi and the rest of her teammates as top-shelf powerhouses individually, Sersi alone is not the MCU's new most powerful hero.

Next: Captain Marvel 2 Can Make Carol Danvers The MCU's Most Powerful Hero Again