Note: this is for book/Salvation spec.
The mastery spec for chalice WP is really simple and straightforward. The spec I use: RoR.builders - Warrior Priest
One of the main differences between chalice DoKs and shield WPs when it comes to 6v6 is the use of Sigmar's Shield so be sure to spec for it:
Spoiler:
Renown spec is straightforward as well: Renown Spec
The gear setup for WP is simple. Currently, I use the 8pc Sovereign setup for the 8pc bonus. I feel that running the full set is beneficial to WP in ranked because the last set bonus can provide additional Righteous Fury in instances where your resource pool is drained while Sigmar's Shield is running, allowing you to cast an extra group hot/absorb/etc. I use the scenario weapons, and my current jewelry besides the Sovereign jewel is 2pc heal genesis with an Exquisite Gunbad Diamond. I have seen others use the Sentinel ring to slot the crit talisman as well. I used armor talismans before the nerf and I still use them now.
The rotation for WP is similar to other aspects of gameplay (e.g., scs/rvr) with the only difference being the consistent use of Sigmar's Shield.
You should still be applying group hots and single target hots consistently to the group and cleansing on CD. Reminder that the WP's detaunt affects the targeted player and the players around them, not just what is in front of you like the DoK detaunt. Sigmar's Shield should be applied to the friendly target in instances of high pressure (e.g., a tank is punted, your other healer is CC'd etc). It is a melee attack, so it works through silence. I generally position myself a bit closer to the melee ball in ranked scenarios to be able to apply it quickly. This does, however, make you an easier target to be swapped to.
Here is an example of group ranked play:
Spoiler:
I also stream WP and DoK gameplay on my Twitch (shameless plug)
Hope this helps!
