Excalibur in the Rust/Playing With

Basic Trope: A weapon that doesn't look very good, but is actually quite powerful.

Straight: Hiro finds a rusty, chipped sword that's clearly seen better days. This sword turns out to be the Dragonsbane, which is still extremely effective against dragons.
Exaggerated: The rusty Dragonsbane looks like it's one bad swing away from snapping in half, but is actually the strongest sword Hiro can ever hope to find.
Downplayed: Dragonsbane hasn't aged well, and takes a second look to see past the patina of rust and the rotted hilt, but it's still recognisable.
Justified: The Dragonsbane was lost years ago, damaged by the same tragedy that befell its original wielder, and left to rust.
Inverted: The Golden Blade of Hope is an incredibly ornate scimitar surrounded by yellow-white flames... but it's purely ceremonial, and totally impractical in a fight.
Subverted: Hiro finds an old, rusty sword and thinks it might be useful... but when he tests it out, it breaks.
Double Subverted: However, he eventually finds a blacksmith who's able to reforge the broken blade into a powerful weapon.
Parodied: Hiro throws away the Infinity-1 Sword for a rusty piece of junk, acting like it's the Infinity+1 Sword even though it obviously isn't.
Deconstructed: Hiro recognises the Dragonsbane and, aware of its fearsome reputation, cleans the worst of the rust off and carries it into battle. However, despite his best efforts to polish it up, the years of neglect have left it brittle and dull and a shadow of its legendary reputation.
Reconstructed: Hiro seeks out the Ultimate Blacksmith, who's able to restore the blade to its former glory. Even if it's never quite what it was, the terror on his foes' faces as they recognise the ancestral weapon more than makes up for it.
Zig Zagged: Hiro finds the rusty sword in the first episode, and is convinced that it's the weapon destined to defeat the Big Bad. He lugs it around for ages trying to find someone worthy of restoring it, while some characters call him crazy and point out other, more powerful-looking weapons, and others quietly suggest that it might simply be a Magic Feather. Even after it's broken in a fight, he keeps Dreaming of Things to Come and pressing on with his personal quest. Eventually it's restored and discovered to be an Empathic Weapon, and his unswerving faith in it makes it all the more powerful.
Averted:
- Hiro finds the rusty sword in the ruins but leaves it, because his preferred weapon is a pistol.
- The sword is old and rusty, and no-one so much as suggests that it might be a hidden artefact of power.
Enforced: The writers are going for An Aesop that you shouldn't judge a book by its cover.
Lampshaded: "You'd think magic swords would come with anti-rust charms as standard..."
Invoked: The sword is an Empathic Weapon that disguises itself as a rusted piece of junk to attract a suitably Humble Hero to wield it.
Exploited: An "Honest John's Dealership" manufacturer of cheap swords covers them with fake rust so he can pitch them as being long-neglected Ancestral Weapons going for a song.
Defied: "Even if this sword was great once, it'd be ruined by all this rust!"
Discussed: "Go for the rusty old sword. I bet it'll turn out to have awesome magical powers."
Conversed: "He has to pick the legendary Dragonsbane out of the Flaming Sword hanging in mid-air, the shining silver one on a plaque on the wall, or the rusty one sitting in the fireplace? Gee, I wonder..."
Played For Laughs: Part of the reason the Dragonsbane is so effective is because every dragon that sees it bursts into uncontrollable laughter and can't concentrate on the battle.
Played For Drama: The Dragonsbane is the only weapon that stands a chance of defeating the dragon god Marduk... but it's been lost for eons, and when finally rediscovered, is in such a state of disrepair that it's practically unrecognizable.

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