You know, one of the things I find most convenient when I’m trying to write Silmarillion fanfiction, is Pengolodh hasn’t listed his sources. (To the best of my knowledge anyway) Which throws some doubt onto his credibility as an unbiased historian. Therefore the dubious accuracy of silm canon is canonical and I have miles of wiggle room to work with. Anything can be canon so long as Pengolodh doesn’t know about it. With that logic I can do whatever I want and still call it canon!
“Did you know you have 30 minutes” and it’s me trying to post a canon compliant byler fanfic before the finale comes out and eventually changes everything
If you follow Overwatch lore in any capacity, you'll notice an out of place element in the world's sci-fi rules. Among nano-technology, genetically altered gorillas, mechs, laser guns, hard light technology, AI, Omnics, and energy shields, there are also spirits. Two dragon spirits and a single fox spirit to be precise. For quite some time the presence of the dragon spirits have confused the Overwatch lore community, as they still have no explanation. Things only became worse when the fox spirit was introduced in Overwatch 2, indicating that these spirits were leaning more towards magic and fantasy than sci-fi. What's worse is that there has been absolutely no scientific reasoning for these spirits, despite even stranger and more mystical appearing abilities (such as Mercy's healing beam) getting scientific explanations (nanomachines). Fortunately, I am here to change that.
It is safe to assume to assume that the dragons and the fox spirit are similar entities, as Blizzard will most likely make it so that Kiriko taught the Shimadas how to get/use their spirits within the lore. Also the dragons and fox spirit seem to be visually similar.
One could theorize that perhaps the spirits are some form of nanomachines or hard-light due to some visual similarities. Now, it wouldn't be impossible for the Shimada Clan to obtain these technologies through illegal means in order to make dragons spirits, but the fox spirit is different. The fox spirit has clearly been a part of the Kamori family for generations. So how did this presumably middle-class family get access to expensive advanced technology before it even existed? As much as I would like a high-tech explanation for the spirits, there is none to be found.
But that doesn’t mean there is no sci-if explanation.
I believe that the spirits are a swarm of hivemind, highly intelligent microbes.
Now, I’m no microbiologist, but I do have an imagination.
A rare breed of bacteria (or any single-celled organism) is able to swarm together in massive quantities due to its ability to generate a hivemind between the microbes. This rare breed of swarming microbes (which I will give the placeholder name of "Sclera") can form itself into humongous (relative to a microbe), complex shapes, such as a fox or dragon. Sclera have become a bit more common due to hard-light emissions and nano-technology pollution in the air, as their presences contribute to the unique environment needed for Sclera to manifest in.
These Sclera Spirits are basically multi-cellular organisms with extra steps, but there are some key differences. Many Sclera have bioluminescence, causing the glow we see. Often times due to Sclera arrangements and quantities the spirits can be translucent, as there are not enough to look opaque constantly. Sclera can also disperse at any time, causing an visual effect similar to disappearing.
Sclera Spirits take the form of animals often through the interaction with said animals. The fox spirit came across a fox to get its form. The dragon spirits most likely encountered several different reptiles. As such, the spirits do have animalistic tendencies. So your headcanons about Hanzo and Genji's dragons acting like dogs can still work. And the fox spirit has made it abundantly clear that these spirits are living, feeling animals due to the fact that it clearly enjoys being rubbed, and hugged, and petted by Kiriko.
Now, for the abilities. Genji gets stronger sword strikes for his dragon fuses with the cellular structure of his (remaining) organs, muscles, and tissues in order to supercharge them. He and the dragon are one. Hanzo's dragon simply splits in two and shifts into a bigger form. The spirit charges in the direction of the arrow and the individual Sclera eat at the skin (or metal) of all that it touches.
Kiriko gets her own paragraph because most of her abilities use the fox spirit (I assume). I'm unsure if her healing ofudas use the power of the fox spirit , but if they do the Sclera most likely have the ability to also repair the broken connections between the cells, similar to Mercy's nanomachines. If the protection suzu uses the power of the fox spirit, then the Sclera temporarily reinforce the cells. Kiriko's swift step is clearly from the power of the fox spirit, and as such simply changes her genetic molecular structure and relocates it; akin to Moira's genetic molecular restructuring used for her fade and Reaper's shadow step. Kitsune rush has the fox spirit run forward output a cloud of Sclera into an area. The cloud takes the form of stepping stones and arches reminiscent of the shrine due to the spirit's connection with Kiriko, and that Kirko associates the fox shrine with protection and empowerment. The Sclera cloud has Sclera briefly fuse with allies in order to enhance their abilities through increasing their reflexes and speed.
There are two reasons why the fox spirit is stronger than the dragon spirits. 1. Kiriko has more spiritual training, allowing her to take full advantage of the fox spirit's power. I doubt Hanzo and Genji signed up for spirit lessons with Kiriko's grandma (and if they did Genji certainly would have not payed attention). 2. The fox spirit is older than the dragon spirits. As said above, the fox spirit has clearly been in the Kamori for generations. We don't know enough about the dragon spirits, (and Sojiro's tale is more about real dragons) so it's safe to assume the dragons came about during the era of hard-light and nano-machines.
TL;DR: The spirits are a bunch of germs in a trenchcoat.
And I like having the spirits be microbes mainly because spirits are said to be all around us and in everything, and microbes are all around us and on everything.