See the issue is that the second guy never showed up. I got the Silver Medallion in Archades, and I completed the four medal quest in Rabanastre and handed them over to the Nu Muo who left, that guy still hasn't shown up at the entrance, and so when I talk to the Nu Muo that is there, he simply replies I met the Silver Medallion guy and doesn't unseal the shrine where the Roblon fight is so I can obtain the final medal. I'm not sure if there was something more to the Rabanastre quest, like if the guy pops up somewhere in town and I need to talk to him or not. I vaguely remember having a similar issue the first time around as well.

In truth, I'm not sure if I really want to deal with Chaos yet, I'll see how the Exodus fight goes first, but I will likely save Chaos for after Giruvegan since he's a Rank III Summon. I'm still having issues distributing the ones I have cause it feels to me like Bushi and Knight get the most bang for their buck while classes like Archer and most of the Mage classes are left in the dust.

As for fishing, while I know I can't undertake the Matamune quest until after I finish the second Gilgamesh fight, I would still like to get the brunt of the leg work down, especially since I have to score perfect scores a set amount of times to unlock new fishing spots until the third area.