Mulligans
This is my big priest which I am currently using to get top 10 legend.
Video guide for deck: https://www.youtube.com/watch?v=IRw0g7I0MKM&t=1181s
Mulligans for aggro: spirit lash, barnes, vargoth, shadow word pain
Mulligans for control: shadow essence, shadow visions, barnes, vargoth, spellstone