Tiamat breathed, and destruction rained down on the city, fire and ice, poison gas and acid, lightning and then the wind and rain from the hurricane. The three blocks between the mages quarter and the castle were slag in moments, at least one thousand men, women and children vaporized instantly.
From the roof of the castle Morgan manned the ancient defenses, huge bolts of energy firing from the large crystal at the center of the roof. As each bolt hit a head of the giant dragon it would vanish, then slowly regenerate, reaching full size as the machine reset to send another bolt. The defenses kept her distracted, at least, allowing the forces to make some headway against the huge armies that poured out of every manhole, well, and crack in the ground.
When Tiamat's breath weapons hit the cast they'd bend and flow around, causing the ground in front of the outer wall of the castle to become a molten pool of fiery toxic sludge.
Woken from their sleep, the mages of the city started to make an even larger dent in the forces. Using walls of force, walls of fire and walls of iron they steered the enemy down blind brick alleys where successive fireballs exploded, turning the alleys into great ovens, the heat enough to kill even those whose magic resistance saved them from the flames.
From the peak of the domed roof of the great pantheon, a brilliant light filled the sky, evaporating the clouds above it. It grew and spread, canceling the storm around the city. A second flash and a great lance of light appeared, held in the hand of lord MacIntyre.
He mounted his great gold dragon and they rushed towards Tiamat, the visor of his great golden armor down and the lance of light held under his arm, the great tourney master on an epic joust.
As he rode it down, it turned to point all its great heads at him, breathing each of the weapons at once, it's bloated body lifting from the ground to take wing.
As the energies hit him, the momentum of the flight carried the lance forward even as he, the dragon and his armor dissolved. When the lance hit the heart of the beast, golden rays of light exploded from the impact, and the dragon beast flew apart in a great explosion, bloody gobs of dragon flesh raining down on the north side of the city.
Of MacIntyre, his dragon, the lance and the great golden armor, nothing remained. Only his great sword, the claighmor named Concord that tamed miles of the Unclaimed Land, only that emerged from the explosion, the hilt swinging wildly as it plunged deep into the foundation of a leveled building. That sword, and flat stones around it, would become a shrine in the next few days. No one, not even any of MacIntyre's many children, would dare remove it.
After the monster dragon was dealt with, the armies of evil broke and ran for their holes, the mages, the defenses and the clerics of good (and neutral) deities too much for them to handle.
A significant military force descended behind them, bringing the battle to Velve-Lloth, but the elders of the dark city had already fled, breaking portals behind them to avoid pursuit.
In the morning, after the battle, Darinna would propose a journey to Conteria to take the war to the Wilderlands itself, and strike at the heart of their dark empire.
With the damage to the fleet from the hurricane, Morgan could spare only one ship for the two month journey from Misty Cross to Harmony, leaving everyone with a choice: Follow Darinna and take arms against the slavers or stay in Misty Cross and rebuild.