Liet was the Fremen alter ego, the other face of the tame planetologist.
There are no more uses of "alter ego" in the book.
Show samples from other sources
Leave her in kneesocks and hair ribbons and let me grow up, unencumbered by my literary alter ego, my paper-bound better half, the me I was supposed to be.
Gillian Flynn -- Gone Girl
His identification with Wolfe was so complete that it was as if he were the writer’s alter ego—and this was excruciating to me, since like countless young men of my generation I had gone through the throes of Wolfe-worship, and I would have given all I had to spend a chummy, relaxed evening with a man like the Weasel, pumping him for fresh new anecdotes about the master, voicing phrases like "God, sir, that’s priceless!" at some marvelous yarn about the adored giant and his quirks andů