as disc:
shield tank, then either mindsear x2 with borrowed time or swpain all adds and mindsear x1. Then spam holy nova til they are dead. For bosses shield tank so you get borrowed time, use dots and penance with borrowed time and cast a hasted holy fire, active PI and cast mindblast, smite smite until penance is up and then just do holyfire>mindblast>penance>smite and keep dots refreshed if they will last most of their duration.