Transcendental Change
From Age of Sigmar - Lexicanum
The Transcendental Change are one of the daemonic Convocations of Tzeentch that currently have the favour of Tzeentch.[1a]
Philosophy
The Transcendental Change favour mutation and alteration as the best way to advance the plans of the Great Mutator. When roused, they wreak havoc with endless waves of transformational sorcery, causing everything in their vicinity - their enemies, their minions, the environment itself - to undergo traumatic physical changes to something that better reflects their vision of the glory of Tzeentch.[1a][1b]
Sources