This reminds me that there’s a quick reference in the Mage Errant series that one of the most powerful characters in the world actively hunts down and exterminates anyone who shows an elemental affinity to a “poisonous yellow stone”, fearing it’s power and potential for unintended harm to the user and those around them.

And the reduction of your Intelligence stat after you wear it

When you’re doing 30d12 to everything within line of sight, movement penalties become less of a concern.

Let my enemies behold their slowly-approaching, inevitable doom!

Wouldn’t it be easier to make radiant armor around the core and use it like a laser with a very restricted line of sight?

As a boring killjoy D&D rules lawyer, I might point out that this will definitely lead to “them” winning, since you are killed when you attune, and therefore can never deal the 1d8 bludgeoning + 30d12 radiant damage.

They won’t be able to see you, but there are like 30 other human senses + made up ones

Look at that child radiate happiness! They’re positively glowing!

Past a certain point death is a formality in d&d, so I don’t think that’s true.

I thought death broke attunement, and you had to reattune after being resurrected?

Welp, that was fun, ready for the new setting next session?

Isn’t attuning only for magic properties that you have to activate? The post seems to treat it like something it just does, like a silver weapon.

Lol. I would obviously need to work in some fun and potentialy precarious radiance immunity mechanic.

Edit: maybe a lord of the rings where you have to destroy the enemies weapon. One option is to detonate it. “Let there be light!”

Magic rock go boom

I’m not aware of any nonmagical items that require attunement, so I think that point also stands. If you were to use such an item without attunement and it were magic, you would do the bludgeoning damage and not the radiant damage.

Nothing to attune to hear. You clap balls, they die. Anyone can do it!

Oh sure, but when I created the plutonium golem, that was too dangerous. Pfft.

Edit: would heavy lead full plate armor help?

The effect is not instant, you only die days later. Short term (like a fight) there is no change.

Would have to be heavy enough that you couldn’t move. You’d be a sitting duck for the bludgeoning damage

Mmm this is a good interpretation. You get radiation poisoning and only die later. If for whatever reason, this item appeared at my table and we needed to adjudicate this, I would totally accept this reading.