The Staff of Qa-Len (simply referred to as the Staff) is an ancient superweapon and artifact of the Solar Empire, capable of calling down a strike from an Imperial satellite cannon in high orbit. It only ever saw two uses over the entire series.
As Kaiser Vlad explains to Countess Ingrid about their predecessors, the Iron Legion, he mentions that the Solar Empire conceived a weapon capable of harnessing the sun's power, using it to destroy the Iron Tower, the seat of Lord Ferrok's power, and all of the Legion with it.
The Staff is first shown in the tutorial mission, as Empress Qa-Len sends a Strike Battalion with a Staff Bearer to deliver the object to the Iron Tower at the climax of the Lightning Wars. When the Battalion falls to a Legion Bomber, the Commander (as a grunt) picks up the Staff to become the new Staff Bearer. The power within the Staff enhances his weapon and armor, allowing him to down scores of Legion infantry, armor, aircraft, and even a Battlestation with nary a scratch. Afterwards, the Staff Bearer's weapon becomes useless as it fuses with the Staff, forcing him to rely on a squad of Grunts to escort him to the Iron Tower, where they ascend to its peak and activate the Staff. In high orbit, the Solar Empire's secret Satellite Weapon charges its cannon and fires, destroying the Iron Tower, Lord Ferrok, and all of the Iron Legion.
In shame of the circumstances that pushed the usage of the Staff, the sacrifices therein, and fear of what its power could lead to, Qa-Len cast the Staff into the frozen wastes of Tundra, where none would disturb its slumber.
Centuries later, Kaiser Vlad of Xylvania found leads on the location of the Staff and set his men on the search. 30 years prior to the start of BWii, he spread rumors of a Western Frontier superweapon amongst the Tundran Territories, causing Tsar Gorgi to invade the Frontier as Vlad led several mining operations in their territory. After General Herman's counteroffensive pushed the Tundrans back, they established a tentative truce before the events of Battalion Wars 1 would come into play. The Xylvanians quietly returned to their homeland as the Staff was nowhere to be found.
Kaiser Vlad spreads another rumor of a superweapon, this time leaking it to the Anglo Isles and goading them to attack the Solar Empire. As the Anglos are repelled and the Empire allies with the Tundrans for a counteroffensive, Xylvania moves to occupy Tundra where Vlad has narrowed down the Staff's location. Thanks to his tactics in making everyone shoot each other, he quickly occupies almost all of Tundra with little effort, though this action merely galvanizes Marshall Nova to reform the Alliance of Nations with the other factions.