in comparison to merits if you already have 5/5 prov merits thats like having another 5 for 10 (+20 def to prov). for shellra, if you already have 5/5 its like having 7.5 merits (-29.34% mdt total)
From BG.
Adds Protect Tier×2 worth of defense when worn being hit with Protect. Can be removed afterwards.For instance, Protect 1 would give 12 defense instead of 10.Adds Shell Tier÷256 worth of magic defense when worn being hit with Shell. Can be removed afterwards.
For instance, Shell V would give an extra 5/256 magic damage reduction.
I think the best use of this (as non-whm) would be to leave this in your idle set.
Sometimes you get re-buffed in battle, but for the most part, you get buffs from your support mages while standing around waiting for things to happen.
Unless there is a very specific reason for you to either need mp on an earring with this effect or to not lose mp on a ring swap, it may benefit anyone considering this item to look at the Sheltered Ring item (which is less expensive, gives the same effect plus 1hp/tick regen, and does not stack with this earring).
While most will be able to use the Sheltered Ring to better effect, the scarcity of this item due to its attainment conditions will likely keep the price high for those few who need/want it.
