Druid Shiro Theory Part 2: Shiro’s Arm
Following on from this post about how Shiro is probably a part-Altean Druid who can do magic and make wormholes, let’s talk about Shiro’s arm for a sec. Specifically: why did Haggar give him the arm, and what is it intended to do?
First up… let’s talk about Haggar. She was the one who gave Shiro his Galra arm. We know she loves combining magic and technology, as evidenced by all the robeasts. Perhaps the most dramatic example is the Komar Experiment:

It’s got that weird black smoke surrounded by the purple glow (obviously magic) and the purple lines running across the metal supports (the technology element). Here’s another, wider view of the whole rig:

And now here’s Shiro’s arm, the first time it activates:

Pretty similar, right? And a moment later, he gets that black smoke and purple glow around the hand, right before he overpowers it and then hacks up a bunch of Galra sentries.

{TBH I just wanted an excuse to include this screenshot}
Of course, the revelation that Shiro’s arm is Galra magi-tech is a surprise to precisely no one at this point, but here’s the thing: the Komar Experiment was powered by a bunch of druids. The black smoke and purple glow all came from them. What’s powering Shiro’s arm?
Now, imagine for a minute that you’re Haggar. You find out one of your captive test subjects is part-Altean and has the dormant ability to do magic. You want to turn him into a powerful magical weapon: a Druid completely under your control, trained to fight and do magic. Do you (a) sit in his cell and spend hours walking him through Sorcery 101 until he learns to control his powers, or (b) fit him with some kind of device - say, a prosthetic arm - that activates his magic for him, against his will if necessary.
Option (b) is really more Haggar’s style, right? And the Komar Experiment is proof that Haggar has zero chill and will happily rip the quintessence out of an entire planet if she wants to, because she’s the real Chaotic Evil of this show.
Now let’s take a look at this picture. This is Shiro’s hand right before he brings the arm under his control:

This looks like Shiro is about to do some druid magic. He looks like he’s about to fling some purple lightening or some of that weird black smoke - but he doesn’t. Instead, he overpowers the arm, brings it under his control, and uses it as a weapon.
So here’s an idea: what if Shiro’s arm is a mechanism that forcibly activates his Druid abilities? It would be powered by his own magic, if that were the case. And the reason why it looks like Shiro’s about to do druid magic is because… well… he is. But it’s being forced out of him, and it’s painful and harmful (like forcing the crystals out of the Balmera is painful and harmful). And now that Shiro is free of Haggar’s influence and control, he reins it in and reduces the magic to a level that doesn’t physically hurt him.
What if every time Shiro activates his Galra arm, he’s actually doing magic?
I mean… that arm LOOKS pretty magical. It has multiple functions that Shiro can apparently activate at will, and it gets that cool purple glow every time he uses it, and it leaves a trail of purple light when he wields it as a weapon.

Does that purple glow remind you of anything?

That’s Allura, right before she throws a bunch of magic back at Haggar and the Druids.
Shiro obviously isn’t consciously doing magic - but I think he might be subconsciously doing it. Just enough to make the arm do whatever he needs it to do. After he uses the arm in the Pilot, Pidge asks him: “Where did you learn to fight with that?” and Shiro says: “No idea.” He clearly knows how to use the arm, and we see him use it multiple times, but he doesn’t remember learning how to use it. His {procedural memory} is intact, but his {episodic memory} is damaged. He’s just working on instinct, intuitively channelling quintessence into the arm to power it up and make it work for him.
We’ve seen Shiro’s Galra arm do multiple cool things throughout the series, and whenever we see it, we just assume it’s the arm that’s doing it. But what if it’s not? What if it’s Shiro? The arm is just a tool - like a magic wand - that helps him activate his Druid powers, but all the functions we see are actually Shiro doing a bunch of low-level magic without fully realising what he’s doing or how he’s doing it. We’ve been crediting the arm, when we should have been crediting Shiro and his ability to manipulate quintessence.



