Perhaps Harry teams up with some of his friends from Hogwarts. Ron could use his strategic thinking, and Hermione her vast knowledge of magic. Together, they create a magical trap for Ebony Maw. Harry, being the main hero, would be the one to lure Ebony Maw into the trap and then use a powerful combination of spells to stop him.
It could be that Harry has to travel to different magical realms to find a weapon or a power source that can stop Ebony Maw. He might visit the Forbidden Forest and get help from some of the magical creatures there. Then, when he finally faces Ebony Maw, he uses this new - found power along with his Gryffindor courage to put an end to Ebony Maw's evil plans.
Harry's magic is based on spells and incantations, while Ebony Maw has more of an otherworldly, telekinetic kind of power. But Harry has the advantage of being able to quickly adapt spells. For example, he could modify the Stunning Spell to have a more powerful impact on Ebony Maw.
Well, perhaps Harry could use his magic skills like the Patronus charm to hold Loki at bay. Since Harry has experience dealing with dark forces, he might be able to outwit Loki's trickery.
In some Harry Potter fanfictions, the 'Maw of the Basilisk' might be a sort of lair. Since basilisks are large and fearsome creatures, their maw (which means a large, menacing mouth or opening) could be the entrance to a hidden place. It could be filled with all sorts of magical elements that are part of the fan - created lore, like ancient spells or magical artifacts that the basilisk guards. Authors might use it as a central location for adventures in their stories, where the characters have to face the perils within.
The plot could start with Thanos arriving in the wizarding world. Harry senses the great danger he poses. Harry would first try to understand Thanos' powers and motives. He might gather information from the Ministry of Magic's records or from ancient magical texts. Then, he would start to form a team of wizards and witches who are willing to fight. As the story progresses, they would engage in battles with Thanos and his minions. Harry would use his Patronus charm to protect his team from Thanos' dark energy, and he would gradually figure out a way to stop Thanos, perhaps by using a combination of powerful spells and the unique magical environment of the wizarding world.
Perhaps the writer of the fanfiction is trying to create a different character arc for Harry. Maybe he has faced so many hardships that he becomes disillusioned. For example, if he has lost too many loved ones and feels that his efforts are in vain, he might stop trying. It's a way to add a new layer of depth to his character.
Maybe Harry has faced so many traumas and disappointments in the wizarding world that he just decides to distance himself from all the chaos. For example, he might be tired of the constant battles against the Dark Arts and the politics within Hogwarts and the Ministry. He could stop caring about his reputation as 'the Chosen One' and simply want to live a quiet life, away from the spotlight and the expectations.
In 'ebony maw x oc fanfiction', a frequently seen theme is the clash of personalities. Ebony Maw is a very distinct character, and when paired with an OC, there are bound to be personality clashes. For instance, if the OC is a very moral character, they might have issues with Ebony Maw's more amoral actions. Another common theme is the journey of self - discovery. The OC might learn a lot about themselves through their interactions with Ebony Maw. There's also the theme of adaptation, as the OC has to adapt to Ebony Maw's world and his ways of doing things.
One possible reason could be that he has been through so much in his original adventures that he's just tired. He might feel like he's constantly being put in new, often contrived, situations in the fanfiction and he simply wants to step away from all the chaos and drama.
Maybe Harry Potter could stop Thanos with the help of his friends. Hermione's intelligence could come up with a plan. They could use time - turners to go back in time and prevent Thanos from getting the Infinity Stones in the first place. Ron could be there for moral support and also use his chess - playing skills to outwit Thanos in some strategic battles.
Well, it could start with Harry gradually noticing how the fanfiction world is not in line with his own values or experiences. For instance, he might find that the magic system is misrepresented in a way that he can't accept.