Obsidian Swords (and Tools)
Adds the obsidian sword, dagger and longsword.
Also adds the obsidian pickaxe, axe, and shovel, all an upgrade to diamond tools.
Each weapon has its uses, advantages, and tradeoffs.
Obsidian Sword: Slightly stronger than a regular diamond sword, at the expense of being slightly slower.
Obsidian Dagger: Quick and durable, with a shorter range and low per-hit damage.
Obsidian Longsword: Very powerful with a long reach, slow but strong swings.