Regalia of the Cleansing Flame

2 pieces: (2) Set: While you are in Shadowform, your Shadowfiend or Mindbender deals 20% additional damage as Fire damage, and the cooldown on Shadowfiend and Mindbender is reduced by 40%.

4 pieces: (4) Set: While you have Shadow Word: Pain and Vampiric Touch active on the same target you gain Dark Flames, which increases the damage done by Mind Blast by 15%.