“Why does the Coptic script have the character ϯ? A lone syllabogram sacralizes the script” – The Coptic character ϯ has several abnormalities within the Coptic script. On the one hand, it is the only syllabogram in the Coptic alphabet. On the other hand, it is not existent in all Coptic dialects and not at all in Old Coptic. Thus, the older explanation that this character did not evolve from a Demotic origin but is a ligature consisting of ⲧ and ⲓ should again be considered. In a second step, it is asked why Coptic has the character ϯ at all. There is hardly any evidence for phonetic reasons, and it is also not convincing to stress a better economy of writing provided by just one sign. Therefore, another explanation is proposed: In Late Antiquity, when the Coptic script emerged, mysticism of signs and numbers (Gematria) was a common exegetic strategy and cultural phenomenon. In this context, the letters ⲧ and ⲓ were, among others, heavily charged with supplementary meaning and also took part in the creation of monograms (like the Staurogram ⳨) and the special writing of nomina sacra. Furthermore, a strong cult of the cross has evolved since Constantine I. and has led to many visual and textual representations of the cross, which the sign ϯ obviously resembles. Thus the implementation of the otherwise not required ϯ can be seen as a sacralization, if not Christianization, of the Coptic Script whose progenitors were used in pagan or at least non-Christian contexts. Therefore, the rendering of the Egyptian-Coptic language by the Coptic alphabet, which consists of some extra characters originating from the Demotic script besides ϯ, became acceptable for Christian texts, although the Demotic script at this time almost exclusively occurs in pagan contexts. Although ϯ has primarily phonographic functions in most cases, it can serve as a visual marker of Christian creed. Thus, this contribution tries to connect Graphematics, Coptology, Patrology and Early Christian Art for a more holistic approach towards the understanding of the character ϯ.