I just realised that this is the barrier. [Huge Spoilers] : r/Undertale
Does the Barrier Affect Saving? | Undertale Amino
Undertale OST: 075 - Barrier - YouTube
ℭ𝔞𝔡𝔡𝔢𝔞𝔱𝔥 on Twitter: "au where all the children are also taken care by asgore and toriel and later when adults they unite to break the barrier and free the monsters #undertale https://t.co/hcpcxvtP6M" /
Barrier | Undertale Wiki | Fandom
Steam Workshop::Undertale Asriel breaks the barrier
Broken Barrier — Weasyl
Barrier Blocks | Undertale AUs Wiki | Fandom
Within the Barrier (undertale) | WEBTOON
322 souls are seen when Asriel breaks the barrier. : r/Undertale