Varyn

Yes.

Yes, but not so specialized.

Hint: It's Cosmere

Okay. Go ahead, guys.

Cadmium, Gold, Chromium, Aluminium?

Iron, Tin, Zinc, Copper?

Is it seen by a viewpoint character on Roshar ... on Scradrial ... on Nalthis ... on Sel?

Looks like you're up, @LabRat

Is it on all Shard worlds, and, if so, is it either progressively or simultaneously?

Is it a unique object? Does it exist outside of the Cosmere? Has it ever been on Roshar?

Already guessed, but wasn't Demoux an atium misting?

Is he related to any of Kelsier's crew members?

Is it one of the characters from TFE Prologue?

The old man, Mennis?

Is it a noble, half-breed, or Skaa?

Mistwraiths?

Is it the Lord Ruler or one of his creations? The Ashmount? The mist? Is it something in nature? Did it exist before TLR's ascension?

What if his fear is using his powers, so he is vulnerable at the exact moment he activates his abilities?

Colour - Grey?

Is it related to any of Sanderson's magic?

Is it a metal? Is it an item of power?

The sun/moon/stars?

Is it a physical object? Is it on every Shardworld? If not, is it on only one?

Is it visible?

A Shard? Hoid? Investiture?