Quote:Well if you take in consideration that Galactus need an elemental converter to drink his shake while Khan doesn't it pretty much cancel out. That and we don't know if Khan was only limiting himself to the life force of beings residing on the planet. Maybe the planet was destroyed as a result of that drain. We don't know why the planets were exploding to begin with only that Khan was responsible.
Actually Galactus does not need the converter because he is quite capable of doing it on his own. Galactus uses the converter because it is more efficient than he is and Galactus doesn't want to waste his own personal energy ripping the planet apart. In fact Galactus uses machines to do his work when clearly he doesn't need to but it is more efficient for him to do so. For instance he is very capable of flying and traveling through space without a ship but why waste energy on such a menial task.