Obsidian Swords are the first kind of sword you get with the mod after diamond. Obsidian swords are crafted with a stick at the bottom of the crafting table and 2 obsidian ingots above the stick.
Damage: 15 (7.5 Hearts)
Note: For whoever decided to edit the page saying "This isn't real bro!," yes, I know it is not real...in minecraft without mods. Notice how the top of the page says, "Obsidian Swords are the first kind of sword you get with the MOD after diamond." Notice the word MOD in there? It's not real in regular minecraft. This mod, currently unreleased, adds obsidian tools, emerald tools, and lava (hardened) tools. In the future, read the page.