But Oda didn’t have to write Garling into the story at all, much less build him up as an important character. I think that him fighting Teach would give him an important spot in the narrative. Garling has history with Xebec, who is clearly Teach’s idol. We know that the grand prize of God Valley, which apparently was even more valuable than the Seiryu DF (one of the strongest Mythical Zoans and therefore one of the best DFs in existence), was stolen from Xebec by the CDs. Garling was declared the Champion of God Valley, so he should have won whatever this grand prize was. There’s no hard evidence yet, but it would make a lot of sense imo if this grand prize was a “Moon God” DF, which would be on par with the Nika DF and therefore > the Seiryu. It would explain why this thing was so valuable to both the CDs and Xebec, and further juxtapose Teach as the anti-Luffy, as was clearly laid out in his introduction.