Prediction: Garlean Primal

[Gula]

I think this is a bit of a leap to be honest.
A lack of ability doesn't equate to an active prevention.
It could simply be that Elidibus being in Zenos' body, means he ADDS this magical ability to the 'magic-less' body.

Yeah this. Garleans seem to have physical prowess and build (that armor ain't light by any means) to compensate. It appears that when you add in a magical Ascian, you basically get a meat suit puppet with a lot of durability to throw out your own magic with.

[Iscah]

I also had the thought of the Garleans possibly summoning a "primal Emperor", I think back in 4.3 when Maxima was talking with Alphinaud, and used the phrase "by the Emperor" where other characters might say "by the gods" - which makes me think okay, so Garleans might be 'godless' but they think of the Emperor with that same kind of reverence... what could possibly go wrong there?

And that's before we even got to the more recent revelations about what's actually going on in Garlemald.

[kikix12]

I think this is a bit of a leap to be honest.
A lack of ability doesn't equate to an active prevention.
It could simply be that Elidibus being in Zenos' body, means he ADDS this magical ability to the 'magic-less' body.

This actually supports her claim. If Elidibus can use magic from a Garlean body, then it DOES mean that it's the soul that stops them from using magic, not the body. That's exactly what ChaseNetwork said.