Etheric Light's function was to instantly upgrade any weapon to the new level cap, which at the time was 34. Lucky players who got Etheric Light to drop within the first few days of the expansion ...

Press X/ A/ LMB on this and you’ll hand them over to Master Rahool in exchange for 10,000 Glimmer. Just like that, you’re all set to get rid of those Destiny 2 Etheric Spirals once and for all ...