With legion shadowpriests loose Leap of Faith, a distinct button and Skill defining ability. Furthermore Shadowpriest will no longer have Power Word: Fortitude. Other than that Shadowpriests bring good utility with Dispel Magic/Mass Dispel and they have Power Word: Shield and Shadowmend to support teammates. The Crowd Control capabilities are fine.
However there is one big issue with Dispel Magic, Mass Dispel and Psychic Horror. The insanity cost. I fully agree with a resource cost, but it is far too punishing to cast these spells in voidform. There should be a talent/artifact trait that reduces the cost of these spells inside voidform by a considerable amount. Or maybe even baseline.
The games “skillfloor” is getting reduced with each expansion and the difference between for example a good and bad death knight or warrior on live realms is mostly definied by damage and teamplay. The game has no such thing as aim like an fps, last hits, apm or gold income like a moba. After you mastered the rotation of your class all there is left to improve is tactics and teamplay. This is especially bad with melee cleave comps. Legion will make things even worse. For example Warriors lose their spell reflect ability, shadow priests lose leap of faith. Removing abilities like Leap of Faith is a huge mistake in my opinion. If you removed it for balance reasons, adjust the cooldown and not remove it entirely.
Mobility and survivability
Three big issues:
Shadowpriests in legion do not have anything to remove slow or root effects
Shadowpriests in legion do not have anything to get out of a bad position
Unlike most other classes/specs Shadowpriests take 100% of enemy damage
In MoP/WoD we had spectral guise to get away in some situations and there is nothing to reduce incoming damage but Dispersion which has a long cooldown. For this reason shadowpriests are an very attractive target most of the time. In Legion there is nothing but huge self heal capabilities.
The self heal of legion shadowpriests are very powerful IF we are able to do a lot of damage. If focused by more than one melee players the self heal is instantly reduced or even shut down. This leads to very frustrating pvp gameplay where you are instantly charged or gripped as soon as they spot the squishy purple blob.
I think survivability should not be determined by the enemy. For shadowpriests it is.
Bring back spectral guise and Dispersion root removal or give a teleport like spell to shadowpriests.
Add passive damage reduction and remove some of the self heal.
Mechanics / Talents / Damage
Other than survivability we are in a very good spot when it comes to killing things. I LOVE Void Torrent, it feels very powerful and fun to use. Currently it is not interruptable. Not sure if intended but according to the tooltip you don’t actually cast a spell but raise the dagger in the sky. *shrug*
Void Shield is powerful combined with void torrent or when in voidform and multi dotting, especially because of the low cd of Power Word: Shield. The other two talents are very weak compared to Void Shield. I think Pure Shadow needs an additional effect and Fleeting Embrace and Vampiric Embrace need a redesign. 3% on direct damage is nothing, the duration, the cooldown.. Vampiric Embrace is a wasted GCD.
I think Mind Trauma and Driven to Madness are much better than the other choices. Combined with Auspicious Spirits and current crit levels (35%) we are getting a huge amount of insanity (maybe too much) just from multi dotting and taking some damage. It seems Driven to Madness gives Insanity for each dot on you. Void Origins does not fit in this tier and does not seem like a pvp talent at all. I’d like to see it go, it’s just a boring dps increase.
Psychic Link is basically a weaker Sphere of Insanity. Very uncreative if you ask me, especially because there is another mechanic overlap with Sinister Thoughts and Legacy of the void doing the exact same thing.
Psyfiend deals a good amount of damage, slows and has a mortal strike effect. I like it and it is a good choice. The only downside is its health (60k) which is less about a dot tick or autohit. Not sure if intended. At least it can be shielded.
I hate niche talents like Last Word. Shadowpriest already has a huge damage modifier (Voidform) and does not need another one. I think this talent should be replaced with a pvp Mind Control. It would have to replace either Psychic Scream or Horror obviously but i was so happy to see the Dominant Mind talent. It just feels great to use in pve and fits the class fantasy perfectly.
I don’t know what to think of Void Shift. It was one of the most hated abilities in MoP but will help shadowpriest survivability. It is also a very strong team utility and it might be too powerful compared to the other two talents.