Undertaker's look, persona, MO, etc. have all gone through very distinct, yet sometimes very subtle changes over the years.
While his debut saw him as a blank zombie-like character, and his association with Paul Bearer and the urn saw him more as a mindless undead soldier to be commanded by a conscious being with the power to control him, other versions of the Undertaker were much more charismatic.
His time leading the Ministry of Darkness, comprised of the Acolytes (Faarooq and Bradshaw, who would become the APA), Mideon (formerly Phineas I. Godwinn, brother of Henry Godwinn), Viscera (formerly King Mabel), and for a brief time adopting members of the vampire faction, The Brood, saw the Undertaker not being led by the mystical powers of the underworld, but using them to lead others. It was an extremely reasonable place for his gimmick to have gone at the time, as no other force in WWE's history had employed such powers over other members of the roster.
Only the Undertaker character had that kind of ability, to not only lead a stable, but to usher in the recreation and repackaging of various midcard wrestlers who, truthfully, weren't going anywhere special. Faarooq, Bradshaw, Phineas, Mabel and The Brood may have been seeing themselves Future Endeavored far earlier had WWE not decided to reimagine Undertaker as a Minister for the darkness that ran through the company.
Recently, as a result of the chaotic 2/21/11 fiasco last month, Undertaker returned after having been buried alive by his brother, Kane, at last year's Bragging Rights PPV. During that time period, I had posted an article, seen here.
In it, I proposed a number of possible options for Undertaker to return to, should he indeed be the mystery man in the promos portending February 21 as a date of note. A feud with Corre and Nexus, a feud with Kane, a heel turn, a job as Raw GM and finally, a repackage of his own. Granted, Undertaker now being referred to as The Last Outlaw isn't necessarily as huge a change as repackages tend to go. He still enters the arena bathed in purple light, still sets fires at the top of the stage, still raises the house lights when he stands on the steel steps at the corner of the ring, still wears a long coat and a wide-brimmed black hat.
However, now his song has been updated to include the Johnny Cash tune "Ain't No Grave," and it really expands on his character greatly. Also part of his new personality is increased vocal cord usage.
The Undertaker in previous years isn't always remembered for the speeches he belted out, the comments he made about this guy or that guy. He's usually remembered for his use of supernatural powers, zipping up jobbers in body bags after applying a Tombstone Piledriver at the end of a match, introducing signature matches like the Casket Match, Buried Alive Match, Hell in a Cell, etc., leading the Ministry of Darkness, feuding with Kane, Paul Bearer and Mankind, and so on.
Now that he's the Last Outlaw, he has a lot more say. It's as if his Deadman gimmick has somehow merged with another gimmick of his that was fairly vocal. Only one other time in his history is he really known for being more of a talker...