using this a reference (i don’t play ptr’s as to avoid spoilers).
blood of the enemy: I think the major power of this is actually interesting. while it is just flat numbers, there is some play around as you want to hit as many enemies as possible. granted i don’t think it’s very much to play around since all you will do is let tanks pull everything together and then let loose with the major power. if i keep my current crit based build on my hunter, this will probably be the major power i use simply because of the extra consistency and synergy i would get. the minor power is just another boring trinket/azerite armor effect. nothing to play with, just another buff to look at.
essence of the focusing iris: i don’t find this one interesting. it’s a straight line of aoe damage that has no synergy with anything the class does. if you need aoe, take it (i expect this to be stacked on aoe heavy fights), if you don’t need aoe, this will probably never be taken as blizz doesn’t like aoe spells being good single target spells. the minor power just seems stupid. on single target fights, this will never be lost, on aoe fights, this power is useless. it only has applications on single target fights or fights where you need to burn down one major add.
condensed life-force: if i’m reading this right, rank 1 of the major power lasts 30 seconds and the rank 2 and 3 last 20 seconds. considering the rank 2 and rank 3 major powers get bonuses (rank 2 gets an aoe spell cast every 8 seconds and rank 3 gives you haste everytime the guardian casts a spell) based on how long the guardian is out, you really limit it’s power. i wouldn’t be surprised if people left the major power at rank 1 until they could boost to rank 3 seeing as rank 2 could be a dps loss over rank 1. the minor power is really boring in my opinion. it’s the old elemental shaman mastery that shoots projectiles at a enemy and rank 3 causes you to do more damage after their hit by one. another thing where you just play the game and ignore the entirety of the spell since it might as well not exist.
purification protocol: I expect this to be the flashy spell of the bunch. it deals damage, then rank 2 gives a small chance to instant kill (assuming this doesn’t work on raid bosses which makes this entirely pointless as an upgrade beyond adds which may be immune as well. seriously, a raid could all take this, spam in on each wave of adds and they’d fall flat in about a second. no way this works on adds.), and rank 3 just increases damage if you kill something in the beam. boring and useless that is hidden by a flashy spell effect. big shame in my opinion as i like spells that involve giant energy beams crashing from the sky. the minor power just adds a passive chance to cleave when you hit something basically. the heal you get from rank 2 probably isn’t even worth it on it’s own so the viability of this power is entirely dependent on the major power.
the unbound force: the major power is probably the second major power crit based build will use. dealing 300% more damage on a crit with up to 5 more times to hit is going to be ridiculous on crit hunters and fire mages. the minor power, while one i would normally call boring, is actually my favorite minor power. when you fail to crit on something, you gain a stack of a buff. at 20 stacks, you get 50%/100% crit chance for 4/5 seconds. this gives a HUGE dps window in which you can use something like instant pyroblasts, bestial wrath, etc. this minor power actually has planning involved in guessing when you’ll hit 20 stacks so you can make the most of the buff. while this is a passive buff, this is one that if you don’t keep track of, you will be wasting 99% of the potential dps. this is the one essence i would heartily recommend keeping roughly the same.