Is a recurring them at this point. Mono has the tendency of leaving people behind. And is very obvious his actions through LN2 are driven by that guilt.
In a world where so many elements are based on emotions and metaphorical aspects of a person psyche being made literal. I’m very much looking forward to know more about Mono.
Why is it such a recurring theme in his dreams?
I'm very excited for that as well! Although, if I may, I would like to add my own spin to this -- I've already written a post about this matter and with the newest pictures of the comic, I think there is more to discuss.
I dont think what you said about Mono being guided by guilt is entirely wrong. But I also don't necessarily agree. I think the good traits he's shown us during Little Nightmares II are completely genuine -- with this meaning his protectiveness and bravery -- but so is the rest of him. Looking back you'll notice that he's always been brash and one to do as he pleased without consultation (even when he's with Six who is someone he values); this is just a demonstration of these traits, verging on the negative, without the addendum of someone he cares about to look after.
The gentleness he exhibited in Six's regards is a lot more evident when put into contrast with how he keeps his distance from Hush.
Thus, with the idea of Mono being inherently caring being disproven (although you could argue that's what the 6th comic from the LN II bundle was trying to convey...) in mind, a conversation about the pecularity of his bond with Six must be brought into the discussion.
If Little Nightmares I was about individuality and its loss -- relationship with the self (as displayed by Six and the Lady), Little Nightmares II is about relationships with others and how they impact you.
With this in the back of your head I'd like to redirect you to the words of the developers of LN II, specifically pointing out the dichotomy of Mono's protectiveness being integral to the relationship in spite of Six's independence.
(Cliffhangers in this context is DIABOLICAL word usage...)
It's presented here as an integral part of his character and, in the game, it is! Thin Man himself replicates the behaviour in its most extreme and twisted form -- that of oppressive imposition.
I believe that through his relationship with Hush we'll see the side of him we are not yet privy to: how Mono acts when he's not influenced by affection. His love (PLATONIC) for Six greatly influenced his entire journey and, as a character, Mono has always been defined by his relationships to her. I think taking this angle with him is not only interesting but also a welcomed (and some will argue, needed) expansion of his character. He's been characterized as a little darling for far too long!!!
This story will end up being an extension on the "relationship to others" theme on its opposite end (how he behaves in regards to someone he is indifferent to) regardless of whether or not this comic turns out to be a prequel or a sequel. I am therefore certain that whatever happens in this comic will do one of two things:
1. Expand Mono's character as an individual;
2. Give us insight on his motivations for holding Six to such a close and high regard. Whether if it was guilt... or fate.
(This moment always makes my eyes water. It feels deeply special.)
I am greatly excited for it!