"I promise not to make an entire sun right here. I probably have some upper bound, but it is definitely astronomical in scale. Demons can and have made stars. Oh, also, if you die I vanish - assuming normal rules are in effect - so if I did want to destroy the planet I'd have to put you off it first or I'd only wind up destroying however much of it sufficed to take you with it. Not that I expect this to be very comforting."