Sentences analysis

Winter City chronicles the childhood and adolescent years of an abandoned, abused and lonely boy named Sam Winters.
During a pronged encounter with a religious cult, Sam Winters' traumatic life experiences manifest as a severe psychological disorder; a split personality. Sam develops a twisted and vengeful dark side that claims itself to be one of the Four Horseman of the Apocalypse.
As the tragic life story of Sam Winters unfolds in the past, the reader will bare witness to the resulting events as they develop in the present; the harrowing ramifications of Sam's upbringing combined with unimaginable personal tragedy. The sad and innocent child lost and in his place, the most terrifying serial killer the world has ever known; The Winter City Reaper.

In my example,
1) I'd like to know whether "manifest" is used as an intransitive verb.
2) And I'd like to know whether "was" is omitted before "lost" and "there is" is omitted before "the most~."

Thank you in advance for your help.