Here is my priest (PogChamp) deck I used to hit legend with this month! will do a writeup if there's any interest!
Mulligan for clerics, any 2 drops, keep extra arms if you have an early minion to play, acolytes are also a good keep in matches where early board is less important. Keep pyromancer vs token druid/murloc shaman.
Main goal of the deck is board control via early game drops and buffing/healing while you cycle through your deck into vargoth/mindblasts and alexstrasza. Mid/late game control through convincing infiltrators and mass hysteria. Can also pressure slower decks with your early drops and buffed minions. Usually always save vargoth for mindblasts.
Will do a more detailed writeup soon!