Allied Tech Tree
Soviet Tech Tree
Epsilon Tech Tree
Foehn Tech Tree
The Harbinger's legend begins in the 20th century, during the days when it was just one of the many projects in the research facilities of Kanegawa Industries. Before the Chinese attacked, research on the particle collision-based weaponry was well underway, and the weapon itself was supposed to give the Pacific Front the ultimate advantage over their enemies, and perhaps even an ace up their sleeve during the Allied leadership negotiations. After most of KI facilities fell into Chinese hands, so did the project and the laboratories, where the tech was being developed. Eventually, the tech resurfaced briefly in the form of several Iron Dragon units, but it was far from what was originally envisioned.
Coincidentally, the same facilities housed massive gunships, equipped with powerful 200mm cannons for siege purposes, concealed from the world for reasons unknown and yet to be launched. However, due to swift actions of the opposing forces, it became impossible for the Chinese to finish the particle collider implemention, and the gunships have mostly been destroyed before they could reinforce anyone's army.
However, the actions of the forces of the then shaping Foehn Revolt resulted in the preservation of both. The Harbinger now acts as Coronia's most powerful aerial weapon, using its destructive particle colliders to level entire enemy bases, and eliminate enemy units of any type, be it on the ground, water or in the sky. The Harbinger can be summoned to the battlefield through a support power after its control tower is built.