Hey I am going to write you a personal AWESOME review of my tips on Inquisition.

Best character in the Inquisition? Vivienne! On Hard you can beat dragons with just her.
1st Spirit skill tree
Barrier- the essential spell (don’t let her auto cast this (X)) add the additional elegant defense later when you have enough points but you shouldn’t ever run out of barrier. Guardian Spirit- useful when you are not paying attention and the barrier disappears and you get hit. Mind Blast- just need it to get to strength of spirit Strength of Spirit- 50% Barrier Bonus
2nd Knights enchanter skill tree get all but Resurgence and Disruption Field Spirit Blade- You should just keep using spirit blade it hits quick for a lot of damage.
Fade Cloak/Declocking Blast- amazing if your barrier does run out. You are invincible for 2 seconds and you can do massive damage if you are inside someone ha. Knights Protector- great for not letting your shield deplete when it lasts 35% longer. Most importantly Fade Shield- the more damage you do the more your shield regenerates.
(Try Resurgence when you have enough points its pretty great, it revives and heals everyone on the field to full health. )
(you should have only spent 11 skill points on the essential so far)
3rd Depends at this point if your have 3-4 skill points left to spend or5-6
A) 3-4 Skill points left Winter skill tree
Fade Cloak- BEST way to travel (If you have 4 points get Frost step)
Winter’s Grasp/ Winter’s chill- great way to freeze people so your warrior can smash them.
B) 5-6 Skill points left Inferno skill tree
Immolate/ Wildfire- your key fire ability+ if your warrior stuns any one you can get a bonus by casting this.
Flashpoint- needed to get further in tree
Clean Burn- More you cast spells the faster your other spells cool down PERFECT for knights blade (it strikes fast and doesn’t cost much mana) then Barrier, Fade cloak, and Immolate are ready to use soon after being cast.
Chaotic focus- adds an additional 50% barrier, ALSO when you cast Immolate you sacrifice half your barrier to do additional fire