I'm outlining the premise for a romance novel with an 'enemies to lovers' dynamic (my favorite genre), set in a post-apocalyptic world where strange, technologically advanced beings known as the 'Arrow Aliens' have invaded Earth. They have the ability to shoot arrows from their foreheads, then the arrows can phase through objects, and suddenly change course, and the object follows the path. They've entered into alliances with some human leaders, but this has led to catastrophic consequences, largely due to the chaos caused by the influx of alien warriors. 

To defeat these superior foes, two opposing factions have formed. They have their own thoughts for how to beat these Arrow Aliens, and sort of are at each other's necks.

Protagonists Jax (female) and Oliver (male), both aged 15, are from these respective factions, with Jax embodying a darker and edgier personality and Oliver representing a more optimistic outlook.

Jax is able to summon bones and shape them into anything, and Oliver can turn any non-living thing into any other molecular object.

Throughout a pivotal confrontation, their sides are forced to unite, albeit with much arguing, and as Jax and Oliver spend time together, they develop romantic feelings for one another

Im currently writing the narrative, considering titles such as

1. Whispers of War

2. Veil of Enmity

3. Broken Alliances