Complex sentence: Juche developed in a similar fashion to Stalinism (officially known as "Marxism--Leninism under Stalin"): a strong leader took power, presenting himself as the sole defender of ideological orthodoxy.
Split into simpler sentences: Juche developed in a similar fashion to Stalinism (officially referred to as Marxism--Leninism under Stalin). That is, a strong leader took power and presented himself as the only defender of ideological orthodoxy.