My theory:
Space Hyung is MC, who saved ML after travelling to the past. The blond one also mert MC there, and is annoyed that MC doesn't remember someone he hasn't meet yet.
Space hyung is actually mc. Basically mc slips through a rift in a dungeon and gets sent to the past when ml was a kid and a slave in the dungeon. Ml is blind so he didn’t see what space hyung looked like.
The blonde guy is just the first esper the mc ever saved and basically he promised the blonde that when space hyung came back and he stopped being ml’s temp guide he would give him a chance at being blonde’s guide. This was years ago though and mc forgot about it bc yk he was too busy fighting with the ml 24/7. Also doesn’t mention it very much in the manhwa but the mc is dumb and he knows he’s dumb so probably partly why he forgot
Spoil me please, like who is space hyung, and what is blondie to our mc saying that the mc forgot about him. Thank youuuu in advance