>>GAMER: I managed to get my soul completely black but the option for the "Tainted" title never appeared. Is this title not in use anymore?
The Tainted title is still available. In addition to being a Paladin whose soul is pallid grey or worse, you must be at least 70th circle and have an active warrant.
If you believe that your character has met all of these requirements, and you're still missing the title, please submit a BUG report in-game for us to review.
GM Cordulia