Playstyle & Rotation
Your highest priority healing abilities will be your holy words, assuming they will do actual healing and not overhealing, as such:
1. Holy Word: Sanctify if grouped allies are injured
2. Holy Word: Serenity if a single target is missing a chunk of health
Next, you want to make sure you keep your small cooldowns rolling on cooldown, they have a great healing per mana spent value and as such
6. Halo (If talented)
Next up is your filler portion of your priority as a Holy Priest - and it will look a bit like your holy word rotation
7. Prayer of Healing if several players have taken damage
8. Flash Heal if someone is in urgent need of a spot heal
9. Heal slow cast used when there’s nothing else really going on
10. Power Word: Shield When you are on the move, and someone is in immediate danger of dying, Power Word: Shield is your best bet at saving them if either of your Holy Word healing spells are on cooldown and Guardian Spirit is on cooldown
- Holy Fire
- Shadow Word: Pain if your mana pool allows you to
- Shadow Word: Death in execute, where the backlash damage will not put you in danger
Be mindful that you are not blindly following the priority list, situations where an ally is about to die will require Holy Word: Serenity or Flash Heal in order to save the player, no matter what the priority list says!
In addition to the aforementioned priority in your general rotation, which will be the majority of your playstyle, Holy Priest does have access to a couple of great raid cooldowns, namely Divine Hymn and Holy Word: Salvation.
Of the two, Holy Word: Salvation is the stronger cooldown despite it getting a slight nerf on the initial hit in the Shadowlands pre-patch. When allocating your raid cooldowns, you need to be very mindful of Divine Hymn’s channel time, it’s a long channel and it's a big loss if you are forced to move at any point during it. Holy Word: Salvation on the other hand is a short cast time resulting in a decent raid-wide initial hit, followed by the two Prayer of Mending stacks on everyone and Renew.
For your utility, if you are moving but not in a hurry you can wait with using your Angelic Feather until you’ve used up your instant healing abilities (Both Holy Words, Prayer of Mending and Circle of Healing), however, once those have been used you can safely use a feather to reach your destination faster. Should the movement be urgent, use your feather as soon as possible.
As a priest, you have access to a purge effect in both Mass Dispel and Dispel Magic so keep an eye on magic buffs on hostile targets. Purify removes diseases in addition to magic effects, so make sure you are tracking both.
Holy priest also has Symbol of Hope which is a 5-minute cooldown, giving all healers in your raid 12% of their missing mana after a full channel. Be aware that it is actually missing mana and not total mana, meaning the more mana you have remaining, the less Symbol of Hope will grant you. It is most commonly used towards the tail end of encounters but some fights allow you two casts or even three if it’s really long, so prepare before the encounter how many uses you expect to be able to get, and where you are able to stand still and channel for 5 seconds.