I can't do this short and sweet, apologies in advance:
My ten year campaign revolved around a bad guy called the Darklord, who was holding the planet itself in its thrall by positioning the last five unicorns over the Well of Stars, the very heart of the sentient planet known as Welstar. The Well was the heart of the planet and the Darklord was a blight upon the world. There were seven heroes who attacked the Darklord's batholith even as a war raged against his undead forces. The Darklord had four minions, each of which wore a magical crown of incredible power.
The good guys consisted of the ragtag human armies of the united Keystone Kingdoms, the Jreasten dwarves (led by their king Boromar Ironsoul) and the united dragon nation (which was under magical compulsion to work together by its self-proclaimed king, Wetzylbaum, a purple dragon). The opposing army consisted of every soft of undead imaginable, including undead giants, undead dragons, wraiths, spectres, etc. Worse, the Darklord's realm drained the life out of people inside it, so it was essentially a suicide mission. This final "World War" featured everything from a 200-foot tall dwarven cannon to magical transforming battle-armor wearing amazon warriors (led by the Queen of Kestyone, of course) to a giant monster battle between the two archmages.
Once inside, the heroes had to battle the Darlord's remaining minions, four in number. They killed the lich who had fallen in love with the wild mage (since both were male, it was a little awkward). They put to rest the lich who had been rejected by a unicorn for being ravished -- she went to her rest peacefully. They went after a third who was such a coward he cut off the crown (still attached to his skull) and fled. They blew the fourth to smithereens. It was down to the Darklord.
The six heroes made for the giant skeletal hand, and from each digit dangled a unicorn in a cage. Atop each digit were a pair of outspread skeletal arms and hands. The heroes had to put their magical weapons (weapons they built up over the campaign) in to power the release of the unicorns. Putting one magical weapon into the skeletal hands meant they clasped shut on both the wielder and the weapon. If the PCs had a lot of time, this wouldn't be a problem. However, the Darklord had transformed into a giant skeletal dragon and was swooping down at them and...they only had four weapons
As the heroes ran for the clasps, the necromancer transformed into a dragon and met the Darklord head on to buy some time. He died in one round. The other heroes put their weapons in, leaving the wild mage with no weapon (he lost his, of course). So he did the only thing he could -- he polymorphed himself into a staff. The items (including wild mage) were drained of all energy, releasing the unicorns. As they fled from the Well of Stars, a gigantic blast of energy burst from it into the heavens, obliterating the Darklord.
It turns out the Darklord knew precisely what he was doing. There were five other living stars (of which Welstar was an immature version) that, upon being alerted by the beam, focused their positive energy on the Darklord's realm and "burnt it off" -- leaving only living beings left. The Darklord and his minions were destroyed, the land restored, and three party members dead. In memoriam, one of the characters named his first born after the necromancer (who nobody really liked anyway). A statue was erected in their honor in Keystone City.
The End.