He doesn't. The name means nothing to Cassian. The only person who's shared much of that era with him for the Timeline is Hux, and Hux has stayed (deliberately) excruciatingly vague.
(The exactly correct torture technique when Cassian wants so badly to know yet also suspects it's more productive and healthy for everyone for him not to focus on that at the exclusion of past and present…)
What he can tell, though, is that Ren says his own name like it's one Cassian should know. Which doesn't always match with anyone else's reality, but in the case of this man—a Force-user…
"Good to meet you," said Cassian. A statement of fact: whether it would prove pleasant or safe or not, by other metrics it was still good.
To ameliorate his ignorance of the name, to get at explanation for it: "You said 'their time is over'… which time is that, for you?" If Ren was from Cassian's past, either his name was less well-known than its owner would like, or Cassian had missed this detail in the messier mental records of early life and Clone Wars propaganda. If his future, Cassian's ignorance becomes utterly neutral—no bearing whatever on either Cassian's knowledge/memory or Ren's fame/significance, just having missed one another.
(And Cassian never expected anyone in the "future" to remember his name. Turns out, some did, but they were those with few degrees of separation—Leia, Luke, Han; Poe also being brought up on Alliance history/mythology from both parents, whom Cassian had personally known… It seemed unlikely Cassian would know of Ren's parents.)
no subject
(The exactly correct torture technique when Cassian wants so badly to know yet also suspects it's more productive and healthy for everyone for him not to focus on that at the exclusion of past and present…)
What he can tell, though, is that Ren says his own name like it's one Cassian should know. Which doesn't always match with anyone else's reality, but in the case of this man—a Force-user…
"Good to meet you," said Cassian. A statement of fact: whether it would prove pleasant or safe or not, by other metrics it was still good.
To ameliorate his ignorance of the name, to get at explanation for it: "You said 'their time is over'… which time is that, for you?" If Ren was from Cassian's past, either his name was less well-known than its owner would like, or Cassian had missed this detail in the messier mental records of early life and Clone Wars propaganda. If his future, Cassian's ignorance becomes utterly neutral—no bearing whatever on either Cassian's knowledge/memory or Ren's fame/significance, just having missed one another.
(And Cassian never expected anyone in the "future" to remember his name. Turns out, some did, but they were those with few degrees of separation—Leia, Luke, Han; Poe also being brought up on Alliance history/mythology from both parents, whom Cassian had personally known… It seemed unlikely Cassian would know of Ren's parents.)
[ooc not to resist]