It supposed to give 5 SP for every mind, body, dark, light or debuff status effect you apply but it simply doesn't work (animation still plays though). I had fatewarper yuki-onna with afflicter who used haunt (-25 SP), pink whisper (-25 SP) and vitiate (-30 SP) and she had only 20 SP left by the end of the turn. So no SP recovery from applying charm, def and evd down.
And quick question - if afflicter was working properly, would it make things like vile dance, poison host or any AoE debuffs basically free or would it only restore 5 SP?