The Assamese opt for neutrality. They neither follow the Shah to war, nor do they oppose his claims. An Andhaira should not fight an Andhaira, let alone abandon one. Of course, the Shah did not actually need Assamese help, but symbolically this is a great blow to Andhairavid pride.
Don't push your luck.
As expected, the Vidyanegroes honour their guarantee, and declare war in protection of the Bengalis. Their defeats at the hands of the Andhairavid Empire have greatly lessened their military capacity, but the Kanth army is still nothing to scoff at. Currently it consists of two main forces, the Raja's army in Kondavidu, and a second, smaller force in Bangalore.
The Gujarati Horde moves to crush the Bangalore army, so as to isolate the Kanth Raja. The Hindus themselves move to attack the Bahmanid Horde. After some brief indecision, it becomes apparent that the Horde will not be able to outrun the Vidyanegroes. The Bahmanid Commander chooses to stand and fight, as a proper Andhairavid gentleman should.
Meanwhile, the Bihari Horde rapidly smashes through the Bengali Republican defenses, reaching and occupying their capital in only a few days.
The Arch-Republicans are slaughtered to a man. The Shah even hears a rumour that the Bengalis allow women into government, but they are all so indistinguishable, it is difficult to verify. The Deva Bengali King is restored to his rightful place, as a puppet monarch in the thrall of Andhaira. He is forced to swear loyalty to the Shah, and to embrace Sikhism. The spineless Bengali agrees without question.
Deva Bengal has now been established as a loyal vassal of Andhairavidia, now all that remains is to once again crush and humiliate the insolent Vidyanegroes.
The Principality of Orissa has also joined the war. Through clever alliances and treaties, the Orissans have managed to stave off annexation for much longer than expected. They are irritating, but hardly a threat. When the Kanth dynasty is finally broken, the Orissans will fall in short order.
The Bahmanid Horde, quite spectacularly, manages to rebuff the main Vidyanegro force. The Gujarati Horde is ordered away from Bangalore to Kondavidu, in an attempt to intercept and crush the Raja. The Horde manages to win a victory, but not decisively. The Raja is sent fleeing deeper into his own territory. The Gujarati and Bahmanid Hordes likewise retreat to reinforce, and to deal with the Bangalore army.
The Shah uses the brief respite to reaffirm the alliance with Assam, and to orchestrate a military alliance with his Bengali vassals.
With the conversion of their Monarch, many loyal Hindus themselves adopt Sikhism. A Sikh majority is quickly established in Deva Bengal. The Shah watches his new puppet with quiet approval.
The entirety of Orissa is quickly occupied. The Shah delays peace talks for a few weeks, waiting for a resolution to the Vidyanegro campaign.
The Bangalore army, which had been besieging Raichur Doab for several months now, is forced to battle by the vastly superior Gujarati Horde. Thousands of Hindus are killed, and the rest are scattered into the countryside. If victory wasn't already certain, this is the nail in the coffin. The Raja's army numbers around 15,000 men, not nearly enough to stand up to the combined forces of Andhaira.
The Orissan Raja offers to pay an enormous monetary concession, essentially emptying his treasury into Andhairavid hands, and to relinquish his claims on Orissa proper and the province of Cuttack. The Shah does not yet intend to annex Orissa, so he decides to take the Hindu gold.
The isolated Vidyanegro province of Parlakimidi is captured, freeing up the Bahmanid Horde to capture Kondavidu.
The Raja fails to win any victories, but he manages to keep his force together as the Gujarati Horde pushes him back and forth through his Kingdom. Attrition takes a dreadful toll on the Horde, but the Commander is confident that the Raja will submit before his Horde is too greatly diminished.
The Vidyanegroes surrender, as the General predicted, after a brief engagement outside Calicut. Their morale pushed to the limits by a string of constant defeats, the Hindus submit to Andhaira. Half of their number are promptly thrown to the goat pits, while the rest are taken as prisoners of war.
All the while. the Bihari Horde besieges and occupies the Vidyanegro capital, the Bahmanid Horde too small to crack open the city. With no army to speak of, and his capital occupied, The Kanth Raja is utterly beaten.
The Shah decides simply to humiliate the Raja. The Vidyanegroes are, much like the Orissans, forced to pay a substantial concession and relinquish their claims on Andhairavid territory.
Now that a peace has been secured, the Shah organises an extravagant wedding between the Deva Bengali Shah and a beautiful Andhairavid Princess. The Bengali Shah is subtly snubbed with a gift of inferior Rajput goats, much to the amusement of the Andhairavid court.
And, just as the war ends, the Kanth Raja dies. The new Raja is a fool, much like his fathers. He has declared his intention to stand against the Shah. This war has resulted in no substantial territorial gain, but the Shah is tiring of these insolent heathens. When war next breaks out, he intends to smash their petty Kingdom asunder.