Tim Lichtnau died on the 26th of December 2024. In this talk we pay hommage by presenting the work he did for his unfinished master thesis, under our supervision. Tim was very talented and planning to start a PhD on homotopy type theory, his passing is also a great loss for the community. He was studying higher Deligne-Mumford stacks in the context of synthetic algebraic geometry. I am deeply grateful to Felix Cherubini for his constant support during the preparation for this talk.