Also remember these lines from TLA.
Anyways, while playing through GS2, two lines said by characters caught me. Mind Read Kushinada in Izumo after learning Sand and she thinks, "If Felix's descendants are ever in trouble, our Takeru will rush to their aid." Takeru is what she's gonna name her son. Also, after beating Doom Dragon, enter the house east of the Inn in Prox. The man says, "I think the rift to the north started receding when the lighthouse was lit." His wife says, "I wonder if that hole up north has stopped growing. What if it starts again?" So there might be an event in Izumo in GSDS, and there might be a much larger Weyard to explore too. Because if the rift visibly receded in the minutes following the lighting of the Mars Beacon, however much time has passed in GSDS should be sufficient for Weyard to be fully nourished and have regained it's former splendor and size. Which is pretty cool!
Hey, looks like I was right on the larger Weyard part! ^_^
Also, one thing I noticed was this.
Kyle, Isaac's father, and the parents of Felix and Jenna were healed by the light of the Mars Lighthouse. Kyle and Felix's dad were Venus adepts, the trait that was passed down to their sons. Mars and Venus share a symbiotic relationship (according to Saturos in GS1). Felix and Jenna's mom was a Mars adept, which is why the Mars Beacon healed her. That trait went down to her daughter.
This means that the elemental associations are genetic. That might be something to throw into the equation.
Lastly, the Isaac/Jenna link is obvious. As for who Garet got together with... Sheba? Hmm... and the new girl... Mia and Ivan?
That's all I can think of. Piers could have been involved with Mia, but the hair would remain blue, wouldn't it?