Since I don't know the exact Unicorn Wars story, it could be that the main characters are different types of unicorns. Maybe there's a brave young unicorn who is the protagonist.
The Unicorn Wars story is likely a very unique and perhaps fantastical one. It might involve battles between unicorns, which could be for various reasons like territory, magic, or some ancient feud. However, without more specific details, it's hard to say exactly what it entails.
The young and brave unicorn soldiers are also quite popular. Their experiences in the war, their hopes, fears, and how they grow throughout the conflict are interesting aspects to write about.
A plot could involve a young unicorn who discovers a hidden power within himself during the war. He struggles with whether to use this power for the benefit of his side or to try and stop the entire war, as he realizes the destruction it is causing to all unicorns.
Since I'm not familiar with any actual 'harry x unicorn lemon fanfiction', it's hard to say for sure. But generally, in fanfictions involving Harry, there could be themes of magic and adventure. With the addition of a unicorn, themes of the fantastical and the purity of magical creatures might be present.
Finding 'harry x unicorn lemon fanfiction' can be a bit of a challenge. First, not all fanfiction platforms might have this very specific combination. Second, the 'lemon' aspect might be a bit harder to find as it could be considered a more niche or even restricted in some platforms. It would be best to start with broad searches on well - known fanfiction sites and then narrow it down by using specific tags related to Harry, unicorns, and any other relevant elements.
You can try searching on fanfiction platforms like Archive of Our Own (AO3). It has a large collection of fanfics across various fandoms. Just type in 'Ginny x Unicorn' in the search bar, and you'll likely find some interesting stories.