I haven't been on TR:TR since it switched over to The Crypt... that said, I'd like to see them gut any theming they have now and install Phantom Theater's Maestro figure into the ride.
They could remove whatever is in Shiva's old location and put in the Maestro figure that was playing the organ in the old Phantom Theater queue there surrounded by a giant pipe organ mock up. As the ride starts, Maestro would play some disturbed Victorian era music that would get faster as the ride goes on. Throw in wind and fog machines coupled with strobe lights, and you have a relatively low cost installation that not only reuses material that park owns, but also brings back a bit of nostalgia. The main entrance and holding area can reuse the old portraits and figures from the rest of the original ride.
Call it Maestro's Mayhem, and you're all done.