How does the Dark One’s Blessing of the Warlock class apply to multi-kills from an AOE attack?

@JeremyECrawford How does the Dark One's Blessing of the Warlock class apply to multi-kills from an AOE attack? Do those temp HP stack?

— Josh Brown (@HeliosHazard) November 23, 2016

Temporary hit points don't stack (PH, 198). If a spell or other feature is meant to break that rule, it would tell you so. #DnD https://t.co/TkAiOgwpyC

— Jeremy Crawford (@JeremyECrawford) November 23, 2016