Also it hit me later:
I dunno if
@Jay13x can confirm this, but I'm 90% sure that is
Ramos.
Ramos was a dragon engine created by phyrexia, and used by Mishra during the brother's war. Urza caught him and reprogrammed him to instead defend the people of Terisiare. As the Sylex Blast happened, Ramos gathered up a bunch of people and planeshifted everyone to Phyrexia — it was a gamble, sure, but it had better odds than the impending doom. Once there, they snuck and found a portal to Mercadia. They went through and crash landed into Mercadia City. Ramos sneaks off to seclusion. The people rebuilt the city, and venerate Ramos as a creator god.
Millennia later the Phyrexian invasion of Dominaria was starting, and Weatherlight and crew flew to Mercadia, meet Ramos, gather up the "
Bones of Ramos" for their legacy weapon and depart. Now, most people read the "bones of Ramos" and, without the modern easy-access storyline, assumed he was dead — but he's not. These weren't actually his bones, they were simply powerstones that Ramos himself had. As the Weatherlight flies away, Ramos destroys Volrath's ship to let them escape. The sight of Ramos helped push the rebellion, and we're meant to assume that Ramos isn't off in seclusion anymore.
Now, it's been a couple hundred years since all this, but Ramos is an immortal artifact. He survived millennia before the Weatherlight, and there's no reason to think he has died since.
