Quote Originally Posted by EusisLandale View Post
If you'd like I can provide another situation where Dark Passenger is the more viable option for spending your MP. Two targets. This is also a situation that occurs fairly regularly.
Abyssal Drain is 720 over 3 GCDs, while a Souleater combo is 700. A Ninja or Samurai being present brings that up to 770.
One Dark Arts brings it up to 840/924, two brings it up to 980/1078. Alternatively Dark Passenger brings it up to 900/970, while DADP brings it to 1180/1250.

So, what we have here with Dark Passenger is an ability that sees proper usage in light aoe situations, on its own, as well as extreme aoe situations, with support from other tools we possess.
What we no longer have with Dark Passenger is an aoe ability that sees use in every situation every single time it comes off cooldown.
I'd admit you are correct here, with 2 targets and 3 globals your single target rotation with DA/DP comes ahead.