Voidium is a new material found in the end, the end's netherite. Its a tier above netherite, while you cant craft armor with it, its tools are POWERFUL.
Sword: has a 25% chance to use the power of dead stars/supernovas power to strike a laser on the hit (can deal 5-15 dmg).
Pick: mines 3x3... How original?
Axe/Waraxe: attacks stupid slow but deals a lot, but A LOT of damage.
Void: its void in your hands that you can place. It cannot be broken even in creative and it absorbs light.
Infused nether star: its just used for crafting the most overpowered thing in the mod.
SUPERNOVA TNT: gets triggered with explosions or you can break it to do that too... Alltho theres a 99% chance youll die because how insane the range of that thing is.
Voidium is very rare and drops one cracked voidium, which can be combined with 3 other ones to craft normal voidium. Youll also need to craft some voidium upgrade templates, which require to put a normal netherite one and combine it with voidium in smithing table.