Excellent.

Zera will settle herself on a convenient outcropping and erect a translucent dome above them with a snap of her fingers. "There, that should keep us hidden. Now, for all her many virtues, I don't think your lovely val'kyr is well-positioned to explain many of the... broader details of this new world you find yourself in. Conveniently, that sort of explanation will also lead in to the nature of my powers and purpose."

She'll sit with Brigid. "Those are details I'm interested in," she concedes. 

"The story starts, as all good things do, when the world was young and wild. To virgin Azeroth from the depths of the Twisting Nether came a group of the most powerful arcane beings in existence: the Titans. Their particular hobby was sculpting worlds to better support intelligent life. And so they set about their work, only to discover that on Azeroth there was a problem- ancient creatures of Void entombed by the nascent world's coalescing from cosmic dust. The Titans' work awoke these great beasts, who quickly bent themselves to twisting and dominating whatever they could. The Void, you see, is a force only slightly less hostile to the forces of Arcane creation than it is to the Light, its twin and opposite. The Titans built gardens, the Voidgods dried them into desert. The Titans built walls, the Voidgods sapped their foundations. The Titans built armies, the Voidgods whispered to the leaders and turned them to empire and conquest. The Titans were mighty but the Voidgods were cunning and subtle, and it was the work of eons that at last allowed the Titans to again seal the Voidgods away well enough that they could resume their great work."

"A brief digression for the nature of magic, at this point. Magic is divided into two categories: the Fundamental Schools, and the Elemental Schools. The Fundamental Schools are the, well, fundamental forces of the universe. Light, Void, and Arcane. Each has their avatar, the Titans and Voidgods I've spoken of, and the third are the Naaru, Void and Light cancel each other out, so left to their own devices the universe would be nothing but stars and emptiness. Arcane is the unbalancing factor, the school of thought, change, intelligence."

"That makes this the second claimed artificially created or influenced world we've run across..." Or at least the second whose inhabitants widely claim it was created or shaped. "And our world was nothing but stars and emptiness for probably a few billion years, but very big stars will make the heavier elements in their cores and scatter those when they die, so eventually you'll get dust that aggregates on its own - it sounds like that happened here? But no intervention is needed for life for us. Though now I wonder - where did the Titans come from?"

"A good question! And not one that has a satisfactory answer. I think it is possible that not even they themselves know for sure."

"Has anyone tried to find out?"

"Chasing down answers from that sort of deep time is... challenging, even for one such as me."

"...Probably theoretical astronomy advances aren't the most urgent thing to potentially import..."

"Likely not."

...Brigid is not really sure what theoretical astronomy has to do with time travel.

She prooobably shouldn't nerd snipe Ling into a ramble about general relativity if she was having trouble with alkahestry basics. Also if she wants to go anywhere else today. 

Shall Zera instead continue talking about magic?

That'd be both useful and fascinating. 

Right. Where was she... Ah, yes. Schools of magic. Next are the Elemental Schools. These focus on manipulating what might be termed emergent properties of the universe. Fire, water and ice, earth and stone, air and lightning, blood, decay, plants, and so forth. The divisions are more arbitrary here, in Zera's considered opinion, though many have constructed elaborate frameworks in which everything can be divided into four schools, or eight, or sixteen. Empirically it does help a mortal learning magic to focus on one singular easily understandable attribute at a time, but there's more room for interpretation when compared with the Fundamental Schools. Additionally, when practicing elemental magic, one must account for the interference of those three prime components- altering the proportion in which they are present can have vastly different effects on a spell. For example, summoning fire infused with Arcane magic will create an elemental, fire that can think, whereas too much Light magic poured into the same spell will create something more on the order of a highly explosive bomb.

This is a fascinating system - how is 'blood' an emergent property distinct from other similar things, or more how are there not infinite 'emergent properties' -

Well. There are. It depends on what stories your culture has, what narratives make sense to you, which way you slice the possibilities so rather than grasping at infinity you can wrap your hands around something right in front of you.

Alkahestry - effectively only works like that for people dabbling in it, learning just the Dragon's Pulse or such. 

It'd be a little disappointing if alternate universe magic worked exactly the same!

Grin! "It's fascinating that it doesn't!"

"You'll have plenty of research to keep you busy once your immediate business is taken care of."

"We still haven't finished even collating all we've learned from one of my allies' own trip into another world."

"You might have to recruit some help."

"Would you be interested?"

"I might be able to make some time."

"Welcome to the research group, then."