So, the Rose is trying to end magic, many of them literally. Let's ignore all the implications that would bring, for now, and focus on something far more fundamental: To end magic, you have to have a definition of magic, so that you know what you should end.
You might say that it is obvious. But let me present to you a few problems with your understanding of magic (in the DF universe).
First, let me take a quote from Magus Hansa's book "The Nature of Magic":
Magic on Lore
Magic on Lore is contained in ley lines, which run across and through the planet like haphazardly-placed latitude and longitude lines. Where these ley lines intersect, there are nexuses of magic which act as reservoirs. There are two central ley lines: the Verix, running North-South, and the Horix, running East-West. To perform feats of magic, a mage must draw on the magic contained in one of Lore's ley lines or nexuses.
Drawing from Ley Lines
The largest nexuses is the core of the planet; it contains the most pure magic available, and is centered where the Verix overlaps the Horix. There is no single mage strong enough to tap into this nexus, though it is rumored the Blue Mage or the Mad Weaponsmith have not revealed the full extent of their power, and they will neither confirm or deny their ability to utilize the central nexus. Normal nexuses and ley lines can be tapped into and drawn from safely, in controlled amounts.
This explains how ordinary, Lorian magic works. But it is far from the whole story. We know that Warlic's powers work differently, and the way that Warlic and Cysero are stated together makes me believe that Cysero's magic indeed is of a peculiar kind too.
Now, let me try to convince you that using mana =/= magic, and vice versa.
If Theano is to be believed, there are non-magical uses of mana, and (at least some kinds of) golem creation is one of them. Thus, it's possible to use mana without doing magic.
Non-Lorian beings and species (like the Atealans and Wargoth) wouldn't be able to use magic if they weren't on lore if they had to go through the process described in Magus Hansa's book. Thus, it's possible to practice magic without using mana (unless they have another mana source, or even generate their mana themselves like Warlic does). At any rate, one can use magic without using the Lorian Ley Lines.
Next, let me give you two more examples that might really confuse you. First, it's Eric Greydawn. His "spell" in the Finale of last years Thankstaking apparently wasn't magic.
Also, there is a clear difference between magic and science. Otherwise, you wouldn't be able to fuse them together into magiscience (since then it would just be "magic" or "science"). This might seem obvious, but I find this fact to make this whole thing even more confusing.
So, what do you think? Have I missed something? Can you come up with a way to make all these facts fit together nicely? Is it even possible to define magic? Should it just be done on a case by case basis?
Was my post so long that you didn't bother reading through it? Have you had enough of questions yet?