What are shadow powers called?

[the Jester]

Arcane powers are spells, divine powers are prayers, martial powers are exploits, etc.

What are shadow powers?

 

[Destil]

Hexes.

And Psionic powers are Disciplines. I'd have preferred talents, or even powers though it's clear why that one's out...

 

[Nymrohd]

I wanted Mysteries and Devotions myself

But yeah they are Hexes, if you have DDI check the assasin.