Throughout Heart of Darkness, Marlow is continually amazed by Kurtz's capacity to inspire devotion, even among those whom he exploits and abuses. When he meets the young Russian wanderer at the end of part 2, Marlow says that he envies the man's romantic spirit of adventure, but adds,
I did not envy him his devotion to Kurtz, though. He had not meditated over it. It came to him, and he accepted it with a sort of eager fatalism. I must say that to me it appeared about the most dangerous thing in every way he had come upon so far.
The Russian shows that he has fallen under Kurtz's spell himself, but also he describes to Marlow the influence Kurtz exercises over the natives, saying that they follow him and adore him. He adds, in justification,
He came to them with thunder and lightning, you know—and they had never seen anything like it—and very terrible. He could be very terrible. You can't judge Mr. Kurtz as you would an ordinary man.
The Russian is a fellow European, albeit a romantic and impressionable one. The natives are even more overawed by Kurtz's strong personality, and this personal admiration for his charisma is combined, in their case, with his use of the latest European technology. This is new to them, and it allows Kurtz what must seem almost superhuman efficiency in gathering a huge amount of ivory and navigating the difficulties of life in the Congo.
Kurtz's confidence in his own power has a profound effect on the natives, and they begin to worship him as a demigod. This adulation contributes to Kurtz's derangement and to the savagery with which he treats the natives who worship him, creating a vicious cycle of insanity and abuse of power.