Just wanted to know, when is the best time to use one, some or all of J'Zargo's flame scrolls? Is it during a mass attack? A dragon fight? Fighting a dragon priest? All three? Just curious in other members' tactics in using them.

I just try to SURVIVE using them at all... but I usually use them when fighting a lot of undead at once. I've never used one on a dragon...

They only work on undead IIRC.

Try casting one and then using Become Ethereal before dashing through a crowd of undead.

J'zargo's Scrolls are more bloody dangerous than ancient dragons lol
If you haven't explored the midden yet, that's a good place to use them.

http://www.uesp.net/wiki/Skyrim:Become_Ethereal

Thanks for the replies. I was curious in the first place because there was a situation recently where I had only a few health potions at the end of Forbidden Legend when you face off against Gauldur's sons' ghosts and the scrolls turned out to be very useful. :3

I use skeletons because they're both weak and undead. I wait until there are at least three of them fairly close, then pop a scroll and run past them. Used this way, just the one scroll will complete J'Zargo's quest since the objective of three uses actually means kill three undead with the scroll(s), not necessarily use three scrolls. Kind of a mini-game for me I guess to complete his quest using only one scroll. Lol.