Another Causal Loop

Manson Everard of the Time Patrol has Merau Varagan, the Exaltationist time criminal, at gunpoint. Varagan keeps Everard talking until his, Varagan's, older self appears above them on a timecycle, fires at Everard and rescues his younger self. One of Everard's colleagues comments:

"'...a causal loop of that sort...didn't he have any idea of the dangers?'"
-Poul Anderson, Time Patrol (New York, 2006), p. 281.

Everard replies:

"'Doubtless he did, including the possibility that he would make himself never have existed...'" (ibid.)

How could Varagan make himself never have existed? He and Everard are in Colombia, 1826. The Exaltationists are from the thirty-first millennium. If Varagan's self-rescue attempt fails, what might happen?

(i) Everard kills the arriving older Varagan and takes the unrescued younger Varagan into custody.
(ii) Everard kills both Varagans.
(iii) Something else?

None of this would prevent Varagan from being born up in the thirty-first millennium. And, in any case, he is unconcerned about preventing his own birth. Everard continues:

"'But then, he'd been quite prepared to wipe out an entire future, in favor of a history where he could have ridden high.'" (ibid.)

An Exaltationist's only concern is to survive into a timeline where his ego is ascendant and his will is unconfined (p. 279). It does not matter to him whether, in that timeline, he has an ancestry, birth or earlier life.