The object you see before you is best described as an ever-undulating ball of liquid mercury with a red glow deep inside its core. The closer your hand gets the more it seethes.
This item has 6 charges and regains all expended charges at dawn.
As an action you can command the orb to transform into any simple or martial weapon of your choice, When you do so it rapidly bubbles and cools before floating into your hand. If it is already transformed you can command it to transform in your hand, or back into it’s orb form, as a bonus action.
Any metal it transforms into is a dark iron, and any wood is ebony. Every weapon has large claws are carved into the handle, and a ruby is embedded into it somewhere. If the weapon it transforms into has the ammunition property each time you attack with it a piece of ammunition made of black iron materializes and then disappears again after it strikes. These weapons always count as magical for overcoming resistances. When not stored in a container the orb floats right beside you just above waist height. If it is not at your side you can summon it to you, and command it to transform, as an action.
Flash of Wrath
When you hit a creature with this item you may expend a charge to create three bolts of crackling black energy that leap from the creature to as many as three other creatures within 30 feet of the first. A creature can be targeted by only one of the bolts. Each target, including the first creature, must make a Dexterity saving throw DC 15. A creature takes 8d6 Lightning damage on a failed save, or half as much damage on a successful one.
As an action you may expend 2 charges to shout a command in Infernal. When you do so choose a number of creatures up to your Charisma modifier (minimum 1) within 60 feet to make a Wisdom Saving throw with a DC equal to 14 plus your Charisma modifier (minimum 14). On a failure a creature falls prone and spends their next turn groveling.