
Spoiler
As much I see the esper and the guide are good friends (10 years) they do not having romantic feelings each other, esper seems to be the 2nd male lead. In this word settings it seems the guide is a bit different than in ither guideverse srories. Guides hunting monsters too, and they having supernational abilities too, the guiding between esper and guide usually is hug and handshake. The word settings isn't dark.

Ml and esper don't have seggs, ml and mc do tho, ml and 2nd ml actually pranked mc that they were going to imprint/were imprinted and mc almost lost his shit until they said they were just joking pretty sure ml liked mc from the beginning, he was actually happy when he heard mc would come to his center and got all dressed up, since mc didn't recognize him and seemed to like 2nd ml he got a little petty Ig?
Also just a fun fact, from what I remember, mc gets kidnapped after 2nd ml confesses to him (he rejected him), he was waiting for ml to come back at the parking lot (he found out the special metal necklace thingy he had on was not from 2nd ml but from ml) and got hijacked by the other A rank esper. He almost got raped by a guard but ml broke into the basement and camouflaged as one of the guards and distracted the other guard so mc could get away. Also the reason for the kidnapping was that the A-rank's guide went rogue, the A-rank believed mc had "tesoro" in him and believed it could repair his guide. It turned out the guide had smth to do with the terrorist attack that killed mc's parent's, "the little kid"(ml, which we know survived, he imprinted on mc when they were under the rubble, cuz mc had trouble breathing and he thought it would save mc), and lots of other ppl. The guide felt guilty for that and wanted forgiveness from mc, mc didn't forgive him but was forced to talk to him by the A-rank (cuz the guide only spoke to mc) and asked one of the kidnapped researchers to hide a gun near the guide, then the guide shot themselves in front of the A-rank, A-rank went batshit crazy, ml and the squad appeared, the basement started collapsing and that's about up to where I stopped reading it, also the ml kinda "sympathized" (not really but idk how to call it otherwise) with the A-rank cuz he realized he would've acted similar(as in went crazy) if mc died, the A-rank tried to protect the dead guide's body as Ml was trying to kill him or smth. Korean mtl is hell so take this with a grain of salt

Checked the last chapters and "since that day, the two have been able to live a peaceful life at the center as an official couple" the ending in the main story, it seems they got engaged?? And mc got jealous abt smth??? as for the side story it seems that there was some drama?? Health problems??? Idk, but it seems to have ended happily too "the two got into the wedding car at sunset. Countless people congratulated them"
Ml is imprinted on mc, ml is the little kid mc tried to protect but thought he failed cuz ppl said ml died (cuz it's confidential info that he's alive, he was experimented on ) also the director is the ml's father.