Kris ahoy!

I personally think Ralsei's fully aware about the player so that's the main reason why he always tries to be with Kris and get along with them. But I just finished playing (once again) chapter 1 and I figured out that Ralsei insists that Kris is the only one who can seal the fountain. And I think that's kinda weird because, unlike undertale time-line, in deltarune not just humans have determination and powerful souls but monsters also do, as long as their lightners, this is mentioned by queen before the robot fight, and we see that berdly was about to create another dark fountain but Ralsei stopped him.

So that made me question that if someone else, not just a human but a lightner, can seal dark fountains, but we just don't know because, as Ralsei said in chapter 1, apparently just Kris can seal the fountain. But as we can see in chapter 2, Ralsei insisted Susie that Kris was the only one who can acted cuz that was "their only talent" and that's when Susie and Ralsei learn S/R-action, so that was Ralsei's trying to give some importance to Kris, and, in fact, getting along with the player. So maybe other lightners beside Kris can seal the dark fountains but is just Ralsei trying to make Kris important just to be pleasant with the player.