Itd pretty easy once you get the hang of it,
Just get the first aggro, or tell your teammates to wait. Pull guardian to the far back and stick as close to the wall as you can.
This is so that u dont get interrupted by other mobs and you dont fling away when he does his big hits. Thats the part where the
other teammates get aggroed by the guardian. Tell your ops to make him dance once in a while, and enjoy the show.