Battle of Vector

The Battle of Vector is a decisive set-piece battle between the Gestahlian Empire and an anti-Imperial coalition, in which the Imperial capital of Vector is assaulted from two angles. Though militarily victorious against the Empire, the anti-Imperial forces fail to bring a final end to the war as the situation quickly escalates out of control, and the Empire would seize the offensive again after a short-lived ceasefire.

Coalition battle plan
The Battle for the Frozen Esper sways the Elder of Narshe to support the Returners in their war against the Empire. The Returners intends to use Kingdom of Figaro’s machines and Narshe’s resources to attack Vector, but the coalition lacks the manpower such a massive offensive would require. A plan is made in which Terra (being half human and half Esper) will cross into the Esper World, negotiate with the Espers and organize an offensive in which a coalition of Returners and Narshe Guards will attack from the north, while the Espers will strike from the east. The desired result is not only an end to the Gestahlian Empire's aggression against the rest of the world, but also the restoration of harmony between Humans and Espers, who has been considered incompatible since the conclusion of the War of the Magi.

Imperial battle plan
18 years ago, Imperial soldiers invaded the Esper world and took several Espers captive. However, they were all thrown out as the Espers closed the gate between the two worlds, making the Esper world inaccessible to humans.

Kefka Palazzo plans to allow Terra to open the gate so the Empire can fulfill the task they failed at 18 years earlier, namely to capture all the remaining Espers and drain them from their powers. Troops are withdrawn from the Imperial Observation Post so that the Returners freely can pass by and reach the gate, and as Terra and her friends move on, Kefka follows closely behind.

Battle
When Terra opens the gate to the Esper World, it becomes apparent that both sides’ planning had been badly flawed; while the Empire had miscalculated the power of the Espers, the Returners had failed to foresee the reaction of their would-be allies as the gate opens. Espers immediately flow out and attack everything in sight, including both Imperial soldiers and Terra’s allies. The Espers then head towards Vector, intending to free their friends who were captured in the previous Imperial incursion into the Esper world. When they discover all the prisoners are already dead, they decimate the city in anger before flying away. Helplessly watching the destruction of their capital, the Imperial Army can do nothing but retreat to the Imperial Palace to avoid bigger casualties.

When the Returners and the Narshe Guards move into Vector, they are shocked and dismayed by the widespread destruction caused by the Espers. It is unknown whether the Imperial forces resisted the allies when they arrived, or if they had already retreated to the Imperial Palace at this point.

Aftermath
Emperor Gestahl surrenders to the Returners, who in turn agrees to help extending the ceasefire to include the Espers. However, the Empire has still not given up its goal of aquiring more magicite. Just as General Leo of the Empire and Yura of the Espers reach a ceasefire in subsequent negotiations in Thamasa, Kefka interrupts and attacks the town. He kills all the Espers and enters the Esper world together with Emperor Gestahl, restarting the war and raising the Floating Continent. This triggers the Battle over the Floating Continent.