the regular dark loop uses 2C,
http://www.youtube.com/watch?v=_fRewX50ucgthat's just one variation, a more optimized one is
...2c 46 edin(red) > 236236e > 5B 2[E] > 66 edin(red) > HC6 2[e] > (possible crossup) > 66 edin(red) EFC into kill
you can also start out with a standard EF 5C 2[E] reset straight into the 2nd part of the above reset
you won't be comboing into blob without a red edin charge, low to the ground EFC (involved red edin anyway), or a 236236E
there's situational combos with dark where you can combo into 236236E from high in the air such as after a neutral throw but you're not going to land in time to land an [E] move
from lower in the air you're going to need to bring them down to the ground first, the only way to do this without an el dorado charge is with something like 5B EFC > standard staircase combo, and of course it would be extremely height specific. after that you would have to combo into 2C 46b edin(if it even works at that point) or find some other way to combo into 236236E so that you can land a 2/5[e]
In other words, there's probably a few ways you can do it, but it's going to be very situational based on height, number of hits, and other factors as well.
the only other move you can use to bring them to the ground and combo with is el dorado j.623red, and that prorates a lot so i'm not sure you'll have much more luck finding a reliable combo here either