Not all weapons are made equal. The majority fall within a single bracket, that of mundane items. Sure, some are better crafted than others. They maybe used a different ore blend in the metal. But largely they were the same, instruments of violence and nothing more.

Of the non-mundane, they carry varying levels of enchantment. Some are slightly sharper or sturdier than the mundane. Others may adjust their trajectory, enhancing the wielder's abilities. Yet others have more interesting effects, like ever burning or instant necrosis of wounds they cause.

The rarest of all are the sentient weapons. They choose their users, and are not chosen. Any lucky enough to wield one was set on the path to becoming a legend, either as a hero or a villain. When not in use, they hide themselves away, only letting a worthy successor find them.

The Hero's Boon is one such weapon, but even more so. It strengths the body and mind of it's chosen, making them into natural legends. When resting it fed them experiences from its long history, making them better and better as time went on. Its form was mutable, shifting to fit their preferred weapon of choice. But despite these gifts, it had one flaw. Those it Chose, could not deny its goal.

Since the death of its last holder, the Boon had gone into hiding. It was made to protect the world, only arising when its very substance was threatened. It took on the form of a metallic mouse, hiding in cities and listening, waiting for its service to be required.

It heard of the rising of a frozen warlord. It heard of their advance, causing a perpetual winter to strike near its ambitions. People fought back, but the few reports to come back spoke of blood frozen in veins, before the frozen bodies reanimated with glowing blue eyes.

The Boon knew it was needed. The world could not survive in permanent snowfall. It instinctively knew where to find its required wielder, part of its multilayered enchantment. The mouse form secured away, leaving civilisation behind.

For days it travelled, never needing to rest. It avoided main routes, shying away from the unworthy. To be noticed would be to be delayed. With the world in dire straits, delays were inexcusable. It scurried onwards, drawing ever closer to its destination.

At last it found it, after delving into the heart of an unwelcoming mountain range. A cave, high on one peak, with a pile of gold inside. Atop this lay a crimson scaled dragon, with a lighter red belly. The dragon opened a single eye as the Boon approached, sniffing as it entered its lair.

"Hrmmm."

It could tell the worth of the Boon, even with one smell. A fortune beyond belief, in the form of a mouse. The weapon stood on its hind legs, staring at it. There was a connection there, even without the sealing of fate. The Boon darted towards the dragon, unafraid of its great claws.

The dragon casually swiped at it, feeling unthreatened by its sudden movement. This was a being that would lat for thousands of years. A little mouse, no matter how magical, could not defeat it. Yet as its paw touched the metal form, it broke apart like water. The liquid Boon flowed up its scales, weaving through them with a pleasurable heat.

The dragon snorted, as it tickled its mind. It was a surprise, but even so, it could sense no malicious intent. Instead it flowed down to its tail, wrapping around blunted spikes. From there it formed a pair of enormous axe-blades, sharpened to a razors edge.

You are Chosen. You are the one to stop the Frigid Expansion.

It spoke with certainty, no room for arguments. The dragon laughed, as it learned of the frozen warlord. They sought to extinguish all fire, and make the world an icy graveyard. With the Hero's Boon prodding, it swore to prove that fire was not so easily beaten. It would show the warlord that ice could not win.