Magiluminescence
Increases movement speed and acceleration Provides light when worn 'A brief light in my dark life.'
1How to craft it
Anvil
the acceleration matters more than the top speed
The bump to maximum running speed is small. What you feel is how fast you get there and how fast you stop. Direction changes become instant, which turns dodging in a corridor from a commitment into something you can correct mid-move. It stacks on top of the Hermes line rather than replacing it, so wear both. The one restriction is that all of it switches off while your feet are off the ground, so it does nothing for you on wings or a mount.
why it is such a good opener
You can build it before you have killed anything, and the light it puts out means no torch occupying your hand while you dig. Very few early accessories do two useful jobs at once. On The Constant it goes from good to close to required, because the glow is far stronger than the early light pets and it is bolted to you rather than drifting behind, which keeps darkness damage off you at a point where you have no better answer.
where the name comes from
Both the tooltip and the yellow gem in the recipe point at Don't Starve, where the same item exists and is built from a yellow gem. The tooltip line is Wendy's inspection quote for it.