Xenoblade Chronicles/WMG

The name Metal Face is a joke that Shulk and his party inadvertently started
Initially  may have had another name (and it may very well have been Black Face), but Xord and other Faces took to calling him the name the Homs kids and the cripple used because they whooped his ass in spite of his nigh invulnerability. This is one of the few rational explanations as to why a robot would call another robot Metal Face, since they all pretty much have metal faces...

Metal Face didn't talk in his first incarnation because he was scared of Dunban.
didn't necessarily like Dunban  He didn't want to risk giving away his identity as he wasn't sure he could beat Dunban   He has no trouble talking when confronted

The Nopon are a deconstruction of Ridiculously Cute JRPG Races
For starters, they appear to deliberately be aware of their own cuteness, as revealed in many sidequests, and use it to their advantage, which may explain their widespread trade empire. At least one Nopon is convinced that his cuteness justifies killing Hodes because he would look cuter riding on an Orluga than they would, and it's amazing how frequently they use their cuteness and helplessness to convince the party to kill loads of monsters. Finally, Riki's Heropon status is granted by the chief not by virtue of his skill, but because he owes the village a considerable sum of money. Far from the idyllic paradise their society seems to be at first glance, the Nopon probably have more deep-seated issues than anyone else on Bionis save

Xenoblade Chronicles is the distant past of Tengen Toppa Gurren Lagann
Just in case the super-sized Humongous Mecha that comprise the game world didn't make it obvious enough, the game seems to have a strong emphasis on Heroic Willpower, screwing destiny and exploring the stars. Fiora pilots a "Mobile Artillery" (mech suit), the Faces are all mecha pilots (in mech suits), and Zanza's 2nd Form even resembles his Shulk-like form wearing an improbably organic-looking mech suit. The settings are even similar (part 1 - heroes in ground battles, part 2 - heroes versus an insanely huge robot, part 3 - heroes fighting nearly omnipotent beings IN SPACE). There's a similar theme, too, in that the hero relies on a weapon (Lagann/Monado) for most of the series for his power, but at the climax of the story, wields the same power on his own.
 * When Shulk declares "a world without gods" in his End of the World Special, he's actually taking the power of creation and destiny and giving it to every sentient being in the world - i.e. Shulk invented Spiral Power. Or at least re-invented it after Zanza revoked it.
 * Also, the Monado(s) are not drill-shaped because galaxies don't exist within Zanza's pocket universe. Shulk invented that, too, when he returned the universe to its original form.
 * Dunban totally plays Kamina to Shulk's Simon, and he's certainly something of a Radioactive Badass. Reyn is Kittan, Sharla is Yoko (complete with the iconic BFG), and Fiora and Melia are basically each half of Nia (Melia with the tragic destiny and royalty bit, Fiora with the Brainwashed and Crazy love interest bit).

Zanza left a piece of his personality inside Shulk

 * At the end
 * Could be the part of Shulk that loved  didn't want to leave. Psychology's weird like that.   but what if he's been leaving pieces of his humanity in ALL of his hosts?

Xenoblade is a distant prequel to Xenosaga, just as Xenosaga was to Xenogears
's experiment  involved the Zohar, and is what lead to  The whole of Xenoblade is set in a self-contained reality overseen by  and controlled through, much like the encephelon dives featured in Xenosaga.