Another possible plotline is that Harry teams up with other thieves in the fanfic. They form a sort of 'thief gang' and plan elaborate heists together. They might target the vaults in Gringotts, not for money, but for some items that can change the fate of the wizarding community.
Perhaps it focuses on his reasons for becoming a thief. It could be that he was forced into it by some difficult circumstances in his life. Like he was wrongly accused of something and had no way to prove his innocence, so he turned to stealing to survive and seek revenge.
One interesting plotline could be Harry's adventures in the afterlife realm where he has to deal with different types of souls. Maybe he meets some souls with unfinished business and tries to help them move on.
Well, one possible interesting plotline could be Harry teaming up with the Autobots to fight a common enemy. Maybe there's a powerful Decepticon that threatens both the wizarding world and the Autobots' home planet, and Harry's magic combined with the Autobots' technology is the key to victory.
Another plotline might involve Harry forming unique alliances with other druids. They could work together to protect an ancient druidic site from dark wizards who want to use its power for evil. This would lead to some exciting battles and magical duels.
One interesting plotline could be Harry's journey to master new paladin skills. For example, he might have to overcome challenges in a magical forest to find a rare weapon or spell that enhances his paladin abilities.
In 'harry is a king fanfic', a possible plotline is Harry having to deal with a rebellion. He would need to use his wits and leadership skills to quell it. Also, his love life might be intertwined with his role as king, like falling in love with a princess from another land which could have political implications.
Perhaps a plotline where Harry discovers a long - lost Templar secret that has the potential to change the balance of power in their world. This could lead to him being both a target and a key figure in a great struggle within the Templar order.
One interesting plotline could be Harry learning elven magic. Since Elrond is an elf, he would have different knowledge of magic compared to what Harry is used to in the wizarding world. Another could be Harry's interactions with other elven characters. He might form unique friendships or rivalries. Also, his growth in a completely different cultural setting than Hogwarts would be fascinating.
One interesting plotline could be Snape initially struggling with his new role as Harry's guardian. He's used to disliking Harry, but as he gets to know him better, he discovers Harry's hidden talents and insecurities. For example, Harry might show an aptitude for potions that Snape had never expected, and Snape has to learn to be a positive influence in Harry's life instead of a critical one.
Well, one plotline could be the main character, perhaps a new healer at Hogwarts, dealing with magical maladies that are beyond the usual. For example, they might encounter a spell - induced illness that spreads among the students and has to find a unique cure using both traditional and forgotten healing methods.
Perhaps in the fanfic, Harry is turned into a snake for a period of time. As a snake, he experiences the wizarding world from a different perspective. He has to learn how to survive as a snake while still trying to fulfill his role in the fight against Voldemort. He might encounter other snakes that are either friendly or hostile, and he has to use his wits to deal with them.