According to John Jackson Miller, this was just a teaser and may or may not be factual. Haazen was pretty much just throwing out name ideas, and it may or may not turn out that Lucien takes the name Sion as per his suggestion; or it may or may not turn out that Haazen's mention of the name may be coincident, having nothing to do with the actual Darth Sion who would arrive later.
Also, according to The Knights of the Old Republic Campaign Guide, Sion was a surviving Sith from Exar Kun's order, so he obviously wasn't Draay.
I think what is more likely is that Haazen himself takes the name of Darth Sion, being a Sith formerly serving under Exar Kun; and Lucien becomes Nihilus.
Originally Posted by a silly noob
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