(Hex) + Images of Remorse + Accumulated Pain
Phantom Pain + Shatter Delusions
They both have their pros and cons. To get the most damage out of the former, you must first have another hex (... not really a condition), and target an attacking target (once again, not hard to find). The latter can target anyone, but the big flaw is that you must invest a large amount into Domination and Illusion to get the biggest effect.
Overall, the armor-ignoring damage and degeneration of both combos are close to equal, and they require the same amount of energy. With no points in FC however, the former takes 4 seconds, while the latter takes only 2.25. Also, the former can only be repeated every 20 seconds, while the latter every 15. The former compensates though because Images is easily spammable for substantial armor ignoring damage.
I don't mind if you compare them in respect to other skills. Overall, I want to know which one is strictly better though.