Thistlecoat  

Level 7 druid spell, so at that level a druid is still more likely to be meleeing and taking hits. NPC hp isn't a huge number so 1 damage will add up vs. not using it.

It's self-cast only with a long duration for the level of the spell, so worth keeping on. Rangers pile on several lines of DS as they get towards level 55. You kind of have to go back in time to have context for any of the spells below level 85 really as there has been a lot of changes to game design philosophy. This was a carefully-tuned and intentional spell in it's era.

It would stack with the other line of druid damage shields that cast on others. Did deeper into the Lucy spell data and it likely stacks with all sorts of things. Sure modern skinspikes potions make it look like nothing, and gear inflation got way out of hand (once upon a time the little bit of +damage might have meant the difference between killing the NPC or dying yourself --good luck dying at level 7 against an even-con NPC if you are in defiant gear).

A low damage DS was long sought after by non DS casting classes for years. If an item with this was your only way to put a DS on yourself and activate the (much-newer) +damage shield stat on your gear you would want it for sure --this is why the bramblecoat-casting chest piece for beastlords is so loved for example.

This will stick with Kiva's potions, but those are only available on the Fippy Darkpaw or Vulak'Aerr servers.