The World of Doors: Adventure from Dream to Space Tree

[No cp, no heroine + space + system + ability + time travel + slow heat] One day fifty years ago, meteors suddenly appeared from the sky, and strange barriers appeared all over the world. Since that day, a very small number of people have gained abilities beyond ordinary people. As time goes by, barriers in various places gradually open, and "light gates" appear in front of the world. Immediately afterwards, various races may appear from the door at any time. This brings both opportunities and dangers to reality. A soul that traveled through time due to sudden death met the Dream Tree, opened the main plot, and the system dispatched tasks, but it actually gave no guidance to novices... In reality, his superficial identity is the healing assistant in the team, and he seems to be powerless. In the secret realm, he turned the tide, but after the matter was resolved, he hid behind the scenes and acted in a low profile. (Don't expect too much from an assistant in the early stage)