Higher Realms

The Higher Realms are a dimension which lay beyond the three-dimensional plane of existence. Exactly how one ascends to the Higher Realms is unknown, though being organic appears to be a prerequisite.

Fiction

2005 IDW continuity

Worried that Cybertron's utopian society would prevent his race from ascending to the Higher Realms, Adaptus advocated that the Guiding Hand wage war on other civilizations to prevent stagnation. The Unremembering

At some point, the Omega Guardians ascended to the Higher Realms, leaving the Magnificence behind. The Ties That Bind The Omega Guardians later attempted to return to the three-dimensional universe to "eat everything". Taking advantage of a small crack between realities in the Benzene Cluster, one Guardian attempted to return only to die in the effort, their four dimensional corpse becoming the Warren. Needing to force open the breach, the remaining Guardians manipulated Adaptus's plans to help bring about their return, though they were ultimately thwarted by the crew of the Lost Light. The Unremembering