Mahler

Mahler was a servant of the Great Intelligence, who was in a position of authority; answering only to Miss Kizlet.

Before falling under the influence of the Intelligence, Mahler was a working class man. However, following his conversion the Intelligence influenced on him caused him to affect a more upper class demeanour; wearing glasses and even changing his accent.

When Miss Kizlet was absorbed into the Wi-Fi, the Doctor altered his propensity to obey; causing Mahler to free her.

Soon after, the Intelligence removed its influence from its servants, which freed Mahler's original personality. (TV: The Bells of Saint John)