In-game dialogue from various NPCs suggest a justification of the With This Herring trope present in Dragon Quest I: you're not the first random adventurer to claim lineage from the Legendary Hero—in fact, you're hardly the most impressive-looking claimant of the lot. Some of the more skeptical don't even believe you until you're slain the dragonlord.
All other heroes of the Dragon Quest series are depicted wielding swords in their official art, while the main character of Dragon Quest V wields a staff in his. This foreshadows that he's NOT the hero of his game! -DannWoolf
The English translation of the first game uses Ye Olde Butchered English, something not used in any of the other games. Why? Well, think about what series defined video RPGs before Dragon Quest came along, and in fact, was its direct inspiration - Ultima. And what was all the dialogue in the Ultima games written in? Ye Olde Butchered English. Perhaps they used it because that's what gamers were used to!
The whole Guilt-Based Gaming in the SNES version of Dragon Quest V seems quite harsh. I mean, why does Bianca have to suffer so much for you to get the Legendary Hero's Shield which can only be gotten by marrying Flora/Nera? And then it hit me. The shield, important as it is, is ultimately a thing. Even though the villain is not involved at all, the whole situation can be distilled into a Friend or Idol Decision. And in such decisions, The Heroalways chooses the girl! Which means if you don't, you're not really a true hero. Well you're not anyway; that'd be your son. Furthermore, you get the Shield anyway even if you choose Bianca, making this a Secret Test of Character. But there may be even more to it than that. As I implied in the Tear Jerker page, it takes a LOT of Heroic Willpower to brush aside what is essentially a guarantee that there will be a Hero soon. But: 1: It's what heroes do anyway (as previously stated) and 2: it could be a statement about The Power of Love winning in the end. After all, how could our Hero have known that the Zenithian bloodline ran through Bianca, who had no evidence of having it, as well as Flora/Nera, who at least possessed a Legendary Artifact. - Donaldthe Potholer
In Dragon Quest VIII, it seems that despite starting out equipped with a club, Yangus' best weapon class is axes. What weapon was he shown wielding when Hero and Trode met him? An axe.