It's heavily homebrew so easiest to explain the item is... My class can deal 1d4 damage as a starting feat, the item gives me the ability to up one dice into 1d6, it persists (if d20 then it's 2d12)
My class can deal 1d4 damage as a starting feat, the item gives me the ability to up one dice into 1d6, it persists (if d20 then it's 2d12)