Eh, depends on what type of creature it is really.I rarely, if ever, use it. My approach is much more direct in over-whelming the creature and works 95% of the time. When it doesn't, just root and re-summon.If you're attempting yellows, that MAY be a good tactic, when coupled with an air pet... still, kind of iffy.Also, I would like to point out that you are wrong in saying it is unbreakable by damage.
(I have a feeling you are thinking of Frigid Winds, not our Shards line, which is what I was referring to and which is amazing for taking down heroics in T6, which is above both of the previous posters)
In any event, like I said above, a conjuror is layered with many varying strategies. The two individuals I am attempting to assist are in a different tier without the benefit of our Ancient Teaching, etc.Hopefully that helps clear up what was confusing you, Lader.--Raygo