beta
I think that the true older brother is just MC again, but from a third timeline, where the first one screwed up the second timeline by not convincing the child MC to follow him, causing ark to gain more power through completing their research. Also they probably screwed around with the dungeons and potentially fostered the world-ending dungeon creatures? So then the gate in the first timeline was meant to be D-rank, but was cultivated by ark which powered up the creatures inside? No idea why they'd do that, or why they'd need child MC for that. Anyway, I feel like it makes more sense to use the characters we've already been shown rather than insert a new brother character. Also sus that they didn't show his face and he made excuses.
Also random, but I feel current MC's identity is going to be revealed due to having the same fingerprint as the child MC. That one chapter where they got MC to sign with his fingerprint felt like it's gonna be relevant again at some point