Theres a lot to suggest shes directly connected to Sylvain. She felt a call coming from the Heart of Sylvain while near it, Heathcliff said she was filled with the light of Sylvain, and she could see the gate to Sylvain from the get-go. Aside from that, Sylvain is the only source of magic we know of (aside from wherever Minerva comes from), and by the Law of Conservation of Detail, theres a fair possibility that theyre connected. Maybe one of Aubreys grandparents was a Sylvan who was exiled to Earth and had children; children that looked human, but retained some dormant magic powers.
Aubrey being part-Sylph would certainly explain a lot, but considering the scale that Griffin likes to work on in his storytelling, this makes the most sense as the way he would incorporate the Flamebright Pendant and Aubrey's powers into the larger world of the story.
- Confirmed in episode 28.
Or rather, Minervas people become the abominations. We see that Aqualungs true form is similar to Minerva, being a glowing, roughly humanoid silhouette. In its final moments, it peacefully accepts death with a nod to Ned. Ducks (and by extension, Minervas and Beacons) entire mission seems to be hunting abominations despite none of them having a previously established connection to the Pine Guard. Also, the origin and source of the abominations is a mystery to the Sylvans and the Pine Guard.
Perhaps some of Minervas people somehow become abominations and wind up on Earth. So, Minervas people select a Chosen One to kill abominations and release them from their monstrous curse.
- Jossed. Episode 16 reveals that Minerva is from Miralaviniax Orbital Body 5, a world which was destroyed by abominations that came out of portals, just like they do on Earth.
That is, they'll go from being a joke character to being important to the plot, likely with a tragic backstory.
I think Jake Coolice or Dani are the most likely candidates.
- Jossed. Episode 30 states that the Sylvans are getting energy from H2Whoa: That Was Fun! now. It is doubtful H2Whoa: That was Fun! has a crystal under it.