Just finished rewatcbing it. Great episode, I liked that instead of taking the easy route of making Ken's older brother a saint or a raging a-holebut their relationship was a lot more complex. Still, I have a few questions.
Was the dark spore a retcon? The episode seemed to heavily suggest that the dark ocean mixed with Ken's emotions turned him evil I think the Japanese version is even titled "When the digivice is dyed in darkness"
What was Ken chosen for? The original
8 were chosen to stop the thing causing the distortions. Daisuke, Miyako, and Iori were chosen to stop the Kaiser and the greater evils behind it. But Ken just seemed kind of chosen at random. (Also despite the Wonderswan games which contradict the series and vice versa anyways, I'm guessing Ken saw the battle with Apocalymon) Like I suppose he and Ryo were chosen to stop
Milleniummon but I would think the old 8 could have done that?
Could Wormmon evolve? As the Kaiser he didn't seem to think he could but he might have been forgotten.
Was Ken's trip to the village of beginnings at least partially in his head? Baby Digimon haven't been able to talk before and it seems unlikely they would know he is the Kaiser even if they retained their memories and were Digimon killed by Chimeramon.