What on earth is shadowy recall?
Item - Priest T16 Shadow 2P Bonus (New) Shadowy Recall effects have their critical damage bonus increased by 100%.
Item - Priest T16 Shadow 4P Bonus (New) Each Shadow Orb consumed for Devouring Plague increases the damage of your next Mind Blast, Shadow Word: Death, or Mind Spike cast within 12 sec by 20%
4 set looks awesome, and may make instant mind spikes decent burst.