After studying the process of Dilgar's homestar going Nova, the Earth Alliance creates the type of strategic weapon not seen outside of the select few of the First One races.
It's work principle is deceitfully simple. By strapping six hyperspace generator together and configuring the, to generate overlaping jump-points in specific configuration, an unstable wormhole is created, that will exponentially grow in it's size as long as the power above certain point is provided to it. The wormhole can feed on the energy converted from the matter that passes through it because part of it would instantly be destroyed by the interaction with the unstable and chaotic form of the overloaded tear in the space-time continuum.
This weapon is useless against enemy ships - EA does not sensors precise enough for a jump-point attacks on the mobile targets an,d, besides, the weapon is a one-shot suicide weapon for the operating crew - the ship on which the generators are positioned will inevitably be destroyed by being near.
The weapon can not be used against planets or asteroid or space stations - the density of the matter is not enough to sustain the ever-growing wormhole.
There is only one type of targets that can be destroyed destroyed by this terrifiing weapon. And those are stars. When initiated in the region of hyperspace corresponding with the core of a star, the unstoppable process of the super-nova is initiated. The process takes up to three years depending on the parameters of the target star and is almost undetectable at first. When it goes far enough to be detected however, there is little anybody can do, for even the evacuation of the target solar system is made almost impossible due to the hyperspace storms and interference with the navigation net generated by the energetic growing wormhole that are stretching for up to a light-year in hyperspace.
After the creation of this weapon, it is immediately banned on the grounds of being too terrifying and with concern of the repercussions of it's use on the future of the Earth Alliance as a member of galactic society. Several prototypes are created, however, to serve as a strategic deterrent and, possibly, to insure the MAD scenario with any and all alien races. No information is leaked to any alien government of course.
Before the Battle of the line however, the government realizes however, that they are facing extinction and there is nothing they can do about it. As a last f*** you to the universe, they initiate "the Ragnarök scenario", sending the sun destroyer weapon to the Minbar (how they obtained coordinates is a separate story, but this is not a place for it). Even as the ships above the Earth are slaughtered, the fate of the Minbar is sealed by the human hand.
And then minbari surrender.
Well, and the author can go from here. The human government is faced with the dilemma of informing minbari about the imminent destruction of their home system and that they have only a year to evacuate. The vorlons are faced with the fact that their circle is, if not ruined, than threatened severely. The Shadows and all other first ones must deal with the fact that one of the greatest weapons in the galaxy is in the hands of the youngest of races. It could be interesting.