[Coldsaturn]

or the closest we can get to it. 
I have to apologize because I love all the boys but Raf has taken my liver hostage so 80% of my cpu is busy with fishie thoughts and that comes at the cost of being proficient at the other LIs' lore to a satisfactory degree. So take this with a grain of salt, but it should still give you some kind of idea of the character. This is not a comprehensive list of ALL cards for the LI, just the ones that can help track the development of their relationship with MC.

(lots of credit to Irandial on tumblr who compiled timelines for Raf-Sy-Caleb. Raf's timeline is mine as I disagree on the order of a few cards, Sy was also modified based on what makes more sense to me, but Caleb is basically irandial's timeline condensed)

PLAYLIST

If I haven't fucked up the order of the videos, this is what we should have 


PRE MAIN STORY
Borrowed Promise
Summer's Echo
Verified Rumor
Stage Observer
Longtime Yesterday
Skyline
Pathless Realm [Anecdote]
Rain's Embrace [Bond]
Endless Summer
Exclusive Aftertaste
MAIN STORY EXPLOSION
MAIN STORY HOMECOMING WINGS
Lucid Dream
Longtime Moments
Hidden Waves
Painful Signal
Intertwined Gold
Deceptive Solitude
Floating Floraletter
No-Return Night
Lover's Whisper
Fiery Embrace

ALTERNATE LINKON
Tainted Cuts

MYTH
Decoherence

ANALYSIS (might keep expanding)
Caleb: Caught in a trauma loop of repetitive grief


P.S. RIP for the kissing sound effects. Caleb's are infamously and hilariously bad.
P.P.S. Following what you said a while ago, I'm not going to straight out tell you which video in the playlist will be nsfw. I can, if you want, otherwise have fun lol

---

Considering how putting these cards in order is a matter of pure interpretation, I'll link different timelines when I find them.

Here an entire notion page with transcripts and summaries.