I think it's about an astronaut that has this little flying thing that acts as his assistant. He has crush on his best friend (a scientist I think). He was planned to come back to earth after a year or so, but to his surprise, earth was destroyed a year ago. All the time he spent talking virtually to his best friend during his time on the space is actually a hologram(?) made from his little assistant.
https://www.mangago.me/read-manga/hate_no_kouya_de_vacances_wo/
Proceed with caution this was a sad read
it's a bl manga/manhwa (i cant remember) about a guy who got isekai'd twice; first is during his chuunibyou phase where he became a spoiled brat that cant use magic but keep being so arrogant, and the second one is when he's an adult. the mc has a jet black hair, and the ml is his knight? i think. they fought during the first isekai, then the mc got killed right after that.
I cant believe I'm cheering for the silver guy lol (peace and love hyunwoo) tho I'd say Iltak hasnt change much (personality wise) with how he doesnt want to communicate. The least Iltak could do is explain things to the silver guy (wont change anything since its all in the past now) but hey thats better than being kept in the dark