I am not sure what happened, this macro was working for a bit but now it is not. What I want it to do is:

cast power infusion every time it is up **this part works**

cast shadowfiend every time it is up **this part works**

cast devouring plague, then shadow word pain. **DOES NOT WORK**

what am i doing wrong?

/target party3
/cast Power Infusion
/assist party1
/cast Shadowfiend
/castsequence Devouring Plague, Shadow Word: Pain