Toby Fox: Tenna is a character who is driven by nostalgia and a yearning to return to an idyllic past that no longer exists. His fear of abandonment - while entirely justified - causes him to lash out and behave in ways which are detrimental to those around him. He has an unhealthy relationship with the others darkners in his life, who in turn exacerbate his fears and contribute to his worsening mental health. He is also quite literally stuck in an environment that no longer cares for him. At his lowest he becomes so intent on bringing the Dreemurrs back that he ends up hurting them and finally driving away his workers for good. In the end Susie understands that Tenna needs a change of environment and a chance to start new relationships, just like the chance she was given. It becomes clear that if Tenna stays where he is now (both in a physical and mental sense) that it will only lead to his own demise. His past love may be gone, but that doesn't mean there's nobody out there who will love him again. This message is only further reinforced by the fact he continues to spiral and exhibit concerning behaviour when he is kept in Castle Town, as opposed to being given to Mettaton, who immediately uses and enjoys his new television (who was an inspiration for Tenna btw. Have I mentioned that? Did you guys see the Mettaton Tenna parallels? Did you see them guys?)