There’s a veilfire you can light in the Watcher’s Reach in Emerald Graves. However, if you search the camp, you wouldn’t be able to find anything that needs lighting and you might be wondering if there is actually something you need to light or not.
Turns out the you there is a Master Lightning Rune schematic you need to light up, but its located outside the camp! It’s just along the pathway you came from (if you came from the base camp)
When you exit the cave, turn left.
Along the pathway, you will see a rune that needs to be lit up.
Light it to receive the Master Lightning Rune schematic.