Context of the quote is more of a simulation of multiple kings statement then one relating to the echo's. He (osiris) specifically references the need for echos isn't needed and then goes on to say the saying relates to Taken Kings instead of his reflections. The potential there is simply giving credit to the fact we didn't then, and don't now, have that power. Therefore, an echo cannot take and when you look at the red legion strike? Something has been recently taking. Quora is too far from earth to be messing with red legion or we simply were never going to see the deployment of additional taken in the area (yet we are) of the dreaming city. Sorry kiddo, but Osiris current theory on the matter would be the reality of Taken Kings most likely.

When someone says something is “the stuff of (insert being here)” with an “s” and the end of that being, it usually means one singular, as there has only ever been ONE Taken King. When I say “that’s the stuff of Oryxs or Savathûns” I don’t mean there are more than one Oryx or Savathûn. Because there are only one of each, right? Same thing here.

[quote][u.2:13] One is a manifestation of Light. The other… reserved for Taken Kings. Better suited for traversing the Sundial because of what lies at its core. [/quote] Context points that aren't singular. And it also points at the fact Osiris is right about the galvanized hive. When you say "That's the stuff of Oryxs or Savathuns" isn't the statement. Given the context and the sundial purpose? This is about the future and the past. Oryx was driven out by a threat to his homeworld and in doing so puts his power in the firm hands of fate and his navigation capabilities, later on, he dies to us and the throne left unclaimed points at a very real possibility that once Oryx was removed from the equation? Savathun and Xivu both had new enemies to pursue and untapped power from the throne of the deceased. If you can't see the danger of that possibility then there is no reason to listen further to you.