Two of Marvel's most famous villains are Marvel's big 2018 event Infinity Wars, it was revealed that the God of Mischief had once decapitated the Mad Titan, to avoid his competition in collecting the power of Infinity. This event, however, was unmade by Loki himself when he regretted his actions and sought to rewrite the past.
Designed to bring the Infinity Stones back to Marvel canon, Infinity Wars was Marvel's big crossover event in 2018. With the movie "Avengers: Infinity War" coming out in the same year and the fight for the stones becoming central in the MCU, Infinity Wars had a lot of expectations riding on it. Though many felt the series from Gerry Dugan and Mark Bagley fell short of expectations it did succeed in rejuvenating the concept of the Infinity Stones and planted the seeds for interesting future developments.
The big reveal of the series was saved for the series' penultimate issue. It showed Loki emerging victorious from the struggle for possession of the stones, and armed with the power of Infinity. He used that to break through the Quarry of Creation and emerge into the First Cosmos. To his disappointment, he found that primordial reality full of other Infinity Stones and their creators, the Celestials. The stones are the skeleton keys of his universe, but they are controlled, serving the will of the unfathomable puppetmasters. Even worse, Loki realized that he already had that experience, when his future self collected all the stones to travel to the First Cosmos, and guessed correctly that future Loki went back in time to try to stop him from making that same mistake, but failed.
The whole Infinity Wars was thus the second version of the same event, but what did actually happen the first time">decapitating Thanos.
This should settle the debate between fans on who would win in a battle between two of Marvel's top villains. The fight, however, was far from a fair one. Loki had already collected the Power Stone, and he was channeling its properties through the armor and sword forged by the dwarves of Nidavellir. He is, after all, the God of Lies, and a fair fight is not exactly his forte. Also, Thanos most likely let himself be killed. After having witnessed his future in the Thanos Wins storyline, he wanted to avoid that fate at all costs, even his own life.
An Infinity Stones-powered Loki is an interesting (and scary) concept, that readers were sadly able to witness only for a very short time. With the issue of the Celestial puppetmasters and the First Cosmos left open, however, perhaps in the future Loki will have to wield the power of Infinity once again to confront that threat. That is, if the recently-resurrected Thanos will have nothing to say in the matter.
