old couple in Sunnyshore City
In Sunnyshore City there's a house up in the northeast corner of the town, where an elderly couple lives, and will give you a small bit of insight into Cyrus as a character. The old woman says; "A long time ago there was a boy named Cyrus that lived here. He seemed to shun others. And he preferred the company of machines. He was a brilliant student, I recall. I often wonder what became of him" The old man tells you that Team Galactic has been up to no good! But they never caused any trouble for Sunnyshore City, and that must be because of their super-strong gym leader! But we as players can infer that the reason the city has been left alone is actually because Cyrus can't bring himself to cause problems for his hometown. Not bothering Sunnyshore, in particular, is telling, since at the beginning of the game all Team Galactic wanted was energy, and Sunnyshore is built off of solar panels, with an electric-themed gym.
grandfather on Route 228
On route 228 there is an old man in the house towards the south of the area, that requires some tricky bike maneuvering to access. Once inside, you'll notice that the house is scattered with books on the topics of machines, spirit, time, and space. The old man notices that you have the gym badge from Sunnyshore gym, and asks to confide in you, and if you say yes, he tells you that his grandson grew up there, "Worn down by trying to live up to his parents' expectations, he found refuge in tinkering with machines." he says, and tells you that he wishes he had taken his grandson away from his parents, and raised him himself, and ends off by apologizing for saying this all to you. You can view the exact names of the books and full dialogue here.
To this day there are still some people who debate whether this man is the grandfather or Cyrus or Volkner, who are both men who grew up in Sunnyshore and have an interest in machines. But I think the books are a dead giveaway that he is in fact, Cyrus's grandfather; why the hell would they include books about time, space, and spirit otherwise?
ultra sun and ultra moon RR post-game
The post-game of Ultra Sun and Ultra Moon involves Rainbow Rocket, an organization made up of all past evil team bosses up until Gen 6, taking over the Aether foundation and attempting to take over the world, or something. I really don't know what their plan was tbh but that's not important! What's important is that this group of baddies includes Cyrus of course. He's either the 3rd or 4th boss you have to defeat, depending on your choice.
He can be found up the stairs to the left-right when you enter the RR castle, where he first asks you if this is "the new world" and then explains that, similarly to the Legendary Adventures in Masters, when he was attacked by Giratina; he ended up here in Alola instead of the distortion world. He does start to spiral into a rant about the human spirit but stops himself when he notices the rotom dex that accompanies the player, asking if he can take a look at it. When the rotom dex does pop out and speaks to Cyrus, he goes silent for a moment, having to turn his back to the player and compose himself. When he turns back to face the player his cold demeanor returns, saying that he won't let anyone stand in his way, and a battle ensues. Afterward, he expresses confusion about how you can transform the emotional bonds with your Pokemon into the strength to defeat him. After the rotom dex pops out again to say how the player makes friends with all Pokemon, something seems to click with Cyrus. He addresses the rotom dex, telling it not to worry, that he won't do anything to this universe, and that he intends to return to his own, and gives you the Galactic key, which will open the boss's room opposite of his. And sends you off by asking; "Had I met you sooner...would things have been different for me...?" This is a quote that has been driving me up the wall completely nuts for 8 years and I still have not been able to get over it even a little bit