Days turned to weeks, and weeks to months.  The simplest solution would have been to let somepony else raise the sun, as the Unicorn Council did in the days before Celestia ascended.  However, given the chaos of the times, nopony had bothered to write down a very accurate account of how, exactly, one took control of the sun, and Celestia’s memories of the event were fragmented images of her sister lying half-dead, of her own coat stained gray with dried blood, sweat, and mud she thought was never going to come out.  She had been maintaining nearly a dozen spells to keep her and her sister alive, and to keep the High Unicorn King at bay.  As he had forced her to her knees, she had seen the now-or-never look in Luna’s eyes, and had dropped every spell, seized hold of her sister’s power, somehow, and blasted the unicorn into dust.  That had been the last thing she remembered until her ponies had pulled her loose from the rubble.  It wasn’t until hours later that anypony noticed that the sun wasn’t moving, and even longer still before she discovered that she could control it.  Even now, she shivered at the memory.