Final answer:
The correct sentence is 'Will had always seen himself as the one and only person who could ever do his job.'
Step-by-step explanation:
The correct punctuation in the sentence is:
Will had always seen himself as the one and only person who could ever do his job.
In this sentence, the commas are used correctly. The phrase "the one and only person who could ever do his job" is a restrictive clause that provides essential information to the sentence and doesn't need to be separated by commas.
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