So looking at this cosmology chart:
If we know that a combination of Light + Void = Fel (based on lore), would Arcane + Void = Nature?
Titan blood is arcane energy, but there’s also Old God blood coursing through the planet, too. Does the combination of both Arcane + Void = Nature, and then creates the Emerald Dream, which are Azeroth’s dreams?
I think this is a lot of crap that they made up and at some point it will stop making sense for whatever they thought back then and they will simply drop it.
The powers the Titans bestow may not be their own. Life, Time, Earth, Magic, and the Dream; all borrowed or stolen from others not by ownership.
I think fel uses a tiny bit of nature too as biofuel.
As for the emerald dream what we can see is there’s the life and death aspect, maybe some bits of shadow corruption leftover from post Xavius
I’m not familiar with the light and void equaling fel part of the lore, where is that from?
While Order is most commonly perceived in reality as arcane magic, on the other hand, Disorder manifests as highly destructive fel magic, a destructive and extremely addictive energy originating as a result of the mutual destruction of Light and Void as they collide on a cosmic scale in the Twisting Nether.
Fel energy counters and is countered by arcane energy, it’s polar opposite.[11] Consequently, Titans are naturally vulnerable to fel magic.
Now that’s something I didn’t know. I know Demon Hunters are getting their third spec next expansion, but now I’m half expecting them to take on a larger role as we get closer to the Last Titan
This chart is very cool to look at but also confusing to follow. Is it like an intricate Venn diagram of what powers overlap with the big bads from each xpac?
Every time I look at Elune it makes me skeptical about life. Like why does it contain arcane, death, and holy magic as well as being related to related to the Shadowlands and Void? Sounds more complicated than titan lore. 
Thats who my parents are!?!
Yeah Elune is a mystery for sure, I wonder if we will learn more about her in Midnight and if she has any relation to the Haranir.
Why bother trying to make sense out of something that even the creator “blizzard” have no idea what it is? The lore is just full of retcon now.
It’s always been a retcon, the first game was just about Orcs and Humans and it’s been a retcon from that ever since.
Elune turned out to be the Winterqueen’s bratty little sister and the only major god that for some reason didn’t get the word about how the Arbiter had been destroyed.