No. Liches are often associated with dark and unethical magic. Harry has always been on the side of good and learning from a lich could corrupt his values.
One main theme could be the battle between good and evil. Just like in the original Harry Potter series, but with the added element of the lich, which represents extreme evil. The story might show how Harry and his friends fight against the lich's dark intentions.
Perhaps a wizard from Hogwarts gets transported to the world of the Lich King. He has to use his magic in new and unexpected ways to survive among the undead hordes. For example, he could use transfiguration spells to change the appearance of the undead, causing confusion among them.
Well, he might become extremely powerful. A lich is often depicted as having great magical knowledge. Harry could learn dark and ancient magic that he wouldn't usually be exposed to at Hogwarts. His skills in combat and spell - casting could be enhanced to a whole new level, making him a much more formidable wizard against Voldemort or other threats.
Well, if Harry Potter becomes a lich in fanfiction, he would likely gain immortality. But he might also lose some of his humanity. His appearance would probably change, becoming more skeletal and undead - like. His magic could take on a darker, more necromantic tone.
One interesting 'Harry Potter the Lich Fanfiction' could be 'The Lich's Influence on Hogwarts'. It explores how the presence of a lich in the Harry Potter universe changes the dynamics at Hogwarts. For example, it might show how the lich's dark magic affects the students' learning and the professors' attempts to counter it.
The story could develop with Harry having to hide his new form from most of the wizarding world. Only a few close friends might know. He'd have to learn to control his new lich powers, which could be very dangerous if not properly harnessed.
Well, 'A Lich's Tale in Harry Potter's World' is also quite interesting. This fanfiction tells the story from the perspective of the lich itself. It gives a different view of the Harry Potter world, showing how a lich might interact with the characters we know and love. It has some really creative plot twists that make it stand out among other fanfictions.
You can try fanfiction websites like FanFiction.net or Archive of Our Own (AO3). They have a large collection of Harry Potter fanfictions, and you can search specifically for ones related to liches using their search functions.
The Lich King has a lot of dark and powerful magic. In fanfiction, characters like Dumbledore might be intrigued by it. He could study it to find ways to counter Voldemort. Maybe he tries to understand the nature of the Lich King's control over the undead to see if there are any parallels with Voldemort's control over his Death Eaters.