A Priest is a great character to play, especially because he is by most recognized to be the best healing class at level 80. Getting a Priest to the level cap has never been really easy or fast. However, I recently leveled an Alliance Priest, after having leveled a Horde Priest 4 years ago, and I must say that the mana-issue while using the Shadow build wasn’t really a problem. You can’t expect to be Holy or Discipline and expect to level up as fast as a Shadow priest. Only if you have some friends that will boost you whenever you want to play you can consider this but if you know you are the one that has to do it, Shadow is the way to go.
Let’s have a look at the talent tree:
As you can see, all Shadow talents are chosen in this build. It speaks for itself that you do move down the talent tree as fast as possible and later take the less important leveling talents like Improved Spirit Tap, Shadow Affinity, Veiled Shadows, Psychic Scream, Silence etc. The talents are quite good though so at a later level they should definitely be taken.
The Shadow tree starts nice with Spirit Tap. While leveling this talent is so great because it greatly improves your mana regeneration after each kill. Once you got your points there you should skip Improved Spirit Tap and put two points in Blackout. Then put points in Improved Shadow Word Pain and Shadow Focus. Put a point in Mindflay once you hit level 20, it’s not that strong in the first few levels you’ll have it, especially if you have a nice wand but it will become stronger and stronger. Use four talent points in Improved Mindblast to reduce its cooldown.
Leave Veiled Shadows for what it is for now and go for Shadow reach and Shadow Weaving, both great talents. Now go straight for Vampiric Embrace which is a nice and free spell that will restore some hitpoints in your fights. Put three points in Focused mind and one in Improved Vampiric Embrace.
Now you can choose either between Darkness and Mind Melt before Shadow Form becomes available! Now this is what you have probably been waiting for while leveling. Your damage will be increased while damage taken will be decreased, it’s just too sweet. Also take the Improved version asap because of the reduced pushback which is nice for your Mind Flay among other spells.
Now take Vampiric Embrace when you get the chance because that is a great damage dealing and mana restoring ability.
All the talents in the downside of the tree are great and it’s up to your preferences which you’d like to take first. You should take Dispersion, a real life saver and mana-generator, whenever you get the chance.