Guesses on Who's Gonna Cameo in RF6
Cecil, who's hopefully found his and Martin's parents along the way now running his own detective agency or acting as a roaming PI. He's still very passionate and curious but more mature and self-controlled.
Julian, who has followed in his mother's footsteps and become a doctor (IIRC, there was an interview in which one of the RF creators said that Julian would probably become a doctor like Simone because he likes helping people or something like that). Bonus points if he's also the mayor (but probably not, as some have speculated that RF6 may take place in the capital of Norad). It'd correspond with Hina's cameo in GOA and let us see how he's been doing in her absence. Also, literally none of the young boys that have shown up throughout the series (Nicholas, Marco, etc.) have ever cameoed in a future title, only some of the young girls (Cecilia in RF2 and obviously Hina), and it's way past time to break that pattern.
Priscilla, who has recovered from her trauma and embarked on travels across the world.
I'm also placing bets that if RF6 takes place in the Capital, then Beatrice, Reinhard, and Scarlett will at least be referenced, if not making a return/cameo, given the former two's ties to the royal family and the latter potentially being the current Warden of SEED (if it's not Ares/Alice).
Some wildcard guesses for cameos include Illuminata (investigating a case that turns out to be part of the plot?), Jake or Cecilia (but only if RF2 Special is in the pipeline at that point--it'd make for a good tie-in), or Kuruna, Ondorus, or Zaid (since RF3 was the last mainline title before GOA).
