The Portal Machine
The Portal machine is a piece of integrated tech built by Hordak from salvaged ship parts. He had been trying to use the portal machine to bring the Horde Armada and Horde Prime to Despondos.
Much later, after Hordak's several failed attempts to restart it, Entrapta enhanced the machine with First Ones' tech. Catra activated the machine, opening a portal that briefly erased all of known Despondos. Currently, it is destroyed by Adora but it did allow Hordak's message through to Horde Prime in the wider universe.