Romseu, Lightning's Grievance

Flash
When Romseu, Lightning's Grievance enters the battlefield, it deals damage to target creature or planeswalker equal to the amount of life you lost this turn.
"My father worshipped Rogudal, and what did his faith beget? An indiscriminate bolt through his heart. I shall show Rogudal that even he is not immune to lightning's indiscriminate destruction."