I did the 50 magic residue, twice, and received a 110 Imbuing scroll and the second time a 105 Imbuing scroll. I saw some reference to 16 times and you get a 120 scroll, though I may have missread.
What about the 50 essences quest, so far I only have 8 and they seem much tougher to get, what is the quest reward for that one?
The Essence quest yields 115 power scrolls - if you do this quest 10 times, and get a scroll binder, you can make your 120 PS by combining those 115's in the binder. Far cheaper (and a lot easier) than doing the 50 fragment quest, which gives a 120 straight away.
Just doing normal monster loot, and unraveling, the average residue to essence return seems to be roughly 10:1 - by normal monster, I mean those in Kings Tomb, Tsuki Wolves, Yamato Warriors (slightly less ratio, but for skill up purposes, you want more residue anyway), Toxic Sliths, Cyclopian Warriors, up to, and including (if you can handle them) Ogre Lords, Arctic Ogre Lords and Titans. Demons and Dragonkin yield a slightly better ratio, but are obviously a bit more to deal with.
