First combo is 5H>IADj.P>j.K>land>5H>sjad.K>j.K>land>5H>sjad.D-2K>j.K>land>5H>Pile
It's a pretty damn hard combo, since the proration is so hard that doing the 5H for the pile will make it a very hard link, and keeping Testament at the right height for everything to connect on is a bitch.
IIRC, the j.P>j.K is done as a link and made so Hase travels further since the backdash hit was pretty much max distance. the iad j.P>j.K and iad j.K>j.K combos pretty much have the same timing for followups, and zdravkelja is right about the momentum thing. If you manage two reps, instead of doing the sj IAD j.D, you may as well just combo into Pile. It's not worth the effort.
Somewhere in this thread, I think, it was asked how to learn the iadj.k>j.K thing. The way it suggested, and how I learned it, was get Potemkin and go to your best side. Do 2D RC>5H>iad j.K>j.K>stuff. Took me a few hours to really understand what was going on for it to work. Just try to make sure the button press is right when you can input moves. You can visually see that you're going further if you do it right.
2D RC>5H>IADj.H is just harder than it needs to be. Just a tight timing thing.
Slayers BnB for a corner 6P FRC is pretty much the sj.H thing.
sj.H>j.D needs to have the sj.H hit on the way up. Best way to practice is 6P FRC>5H>sj.H>j.D-2k>j.K>stuff in the corner on light...Sol. Can also do 5K>6P if they're crouching or if it's on CH.
Full combo is something like...5K>6P FRC>5H>sj.H>j.D-2k>j.K>land>5S/K>j.S(2)-2K>j.K>dj.H-2K>j.D Does like 239 damage on Sol.
http://www.youtube.com/watch?feature=player_detailpage&v=1SMloai5xaw#t=26s video of it.