A third plotline could be that Harry discovers new magical abilities or artifacts during his fights in multiple wars. These newfound powers or items could change the course of the wars he's involved in. He might also have to deal with the politics of the different factions in these wars. In some crossovers, there could be power - hungry leaders who want to use Harry's fame or his powers for their own gain, and he has to outwit them while also fighting on the front lines.
Another plotline might involve Harry struggling with the moral and ethical differences in the various wars he's fighting in. He could be conflicted about the rules of engagement in some of these new battlefields, which are different from what he's used to in the wizarding world. For example, in a war where non - magical means are also used, he has to figure out how to balance his magical powers with other combat techniques. Also, his relationships with other characters could be explored, like how he forms alliances or rivalries in these new and dangerous situations.
Hermione could be one of his allies. She's smart and resourceful, and her knowledge of magic could be very useful in different war situations. Also, Ron, with his loyalty and his own combat skills, would be a great help.
Maybe Harry discovers a hidden part of the wizarding world that uses guns as a form of magic - enhanced weaponry. So he has to learn how to use these guns in combination with his magic to defeat a powerful villain. For example, the guns could be enchanted to fire spells instead of normal bullets, and Harry has to master this new form of combat.
In some fanfics, it could be a competition gone wrong. For example, a friendly sparring match between Percy and Artemis turns into a full - fledged fight due to some external interference like a magic spell or a cursed weapon. This could lead to a series of events where they have to put aside their differences and work together to solve the problem that caused the fight in the first place.
Maybe Harry leaves the wizarding world and uses his magical skills in the muggle world as a mercenary. He could be hired for dangerous jobs that require a touch of magic but need to be kept secret from the muggles.
One possible plotline could be that Luke has been corrupted by some dark force, and Percy has to fight him to save their world. Percy might be reluctant at first because they were once friends, but the greater good forces him into action.
One possible plotline could be Luke's discovery of a long - lost Jedi technique during the Clone Wars. Maybe he uncovers it while on a mission to rescue some clones. Another could be his interaction with famous Clone Wars era characters like Anakin or Obi - Wan. He might learn valuable lessons from them that shape his future as a Jedi.
One possible plotline could be them collaborating on a charity event. They both come from high - profile families and might be involved in fundraising and helping the community together in the fanfic.
One possible plotline could be Harry coming to power after a great war in the wizarding world. He then has to deal with rebuilding and unifying the different wizarding communities under his rule as emperor. He might face resistance from some traditional wizarding families who don't want to accept a new form of government.
One possible plotline could be that Cyrus Black is revealed to be a long - lost relative of Harry, and he takes Harry under his wing to train him in a special kind of magic. Another could be that they meet during a dangerous adventure and have to rely on each other to survive.
One possible plotline could be that it's a moment of unexpected playfulness between Draco and Harry. Maybe they are in a truce situation, and Draco, in a moment of light - heartedness, decides to tickle Harry as a form of friendly teasing. It could be a way to show a new side of their relationship, moving away from their usual rivalry.