Cassian is a recluse, seen in multiple sightings to be avoidant of others. However, interviews are made where he speaks about his frustration with returning to real life, sleep research, parasomnia, etc. to be topics that he openly discusses with people. He has made childish remarks through these, with him forgetting his real age and claiming he is 13 years younger than he is. He only interacts openly with those closest to him, spending most of his time in his laboratory. 

Mid pitch, masculine, late 20s. Slightly uneven, off-beat delivery with irregular stress on certain words, giving his speech a distinctive, thoughtful rhythm. Noticeable Swiss German accent, with softened consonants and subtly rounded vowels. Tone is grounded but emotionally reactive. It can come off a bit juvenile or stubborn when arguing, yet shifts into a more intense, almost raw sincerity when dealing with grief, nostalgia, or pride. Pacing varies with emotion, from halting and searching to more insistent and sharp, while maintaining an overall earnest, lived-in quality.