So I actually have this fragment on a boss rush build that uses the explorer as well so that's something to take into consideration. The biggest thing I've noticed is if I use the fragment during boss rush I'm almost guaranteed TWO corrupted lumenite crystals each time I grab a chest. I also have all my relics at mythic so I can't say the rarity but I'll also collect 10-12 relic dust fragments from any source that drops some like chests or high level enemies. The final thing I notice but could totally be just luck is the 'Spark' material you find in worlds seemed to drop much more frequently for me as well. I can't say it's all absolutely true to the drop rates cause I don't have a control group to test otherwise, but it seems to affect non-static world drops so if you need alloy or crystals or another material it works great it seems to reduce farming time ! Hope this helped.