I didn't know he was going to turn out to be a minor character
It's certainly true that we didn't know exactly when it was going to happen, but as the body count of major characters began to pile up during Claude's time, it was increasingly apparent to those familiar with the way DS operated that 1970PT was racing toward its conclusion.
And when men of mystery appear on TV shows, or in books, etc., eventually the mysteries are solved by the end, usually anyway. That's why we stay tuned.
Well, Claude's history is revealed reasonably enough, at least as far as it pertains to the events of 1970PT:
[spoiler]He apparently knew enough about the Occult to harness some of its powers, he apparently thought nothing of using them on and/or in conjuction with his psychic girlfriend Roxanne, but at the same time he was willing to hand her over to Stokes in exchange for money. On that last point all I have to say is, "What a winner!"
[/spoiler]
CN's personal backstory
Sadly there wasn't enough time for that. What might have been really interesting may have been if he'd arrived sooner, like, say, shortly after Roxanne was discovered. But alas...
he disappears in a puff of smoke (not literally... I forget his end) and that's it.
[spoiler]Tim Stokes killed Claude for his betrayal of making Roxanne speak and thus destroying Angelique.[/spoiler]
If he'd just been some guy, it wouldn't have mattered, but they drew us in with the frequent mantions of the name with that air of importance, and he had this "presence" and delivery...
Sometimes short term characters are built up specifically so that their deaths are that much more shocking - especially when there's no clue whatsoever within the story that they're going to be short term. It's a common writing device.
(And quite honestly, I
still have yet to get over the death of Neal Keller Alcott (played by the beautiful and talented Mary Kay Adams) on ATWT all the way back in '93.
Longtime ATWT fans will know what I'm talking about...)