This story is a sequel to Graphs

...or Internal Conflict if you don't like math.

Rainbow Dash has been having an awesome time with her clone. Her friends have noticed.

After some well-meaning nagging and manipulating, Rarity has finally convinced Twilight to cast the cloning spell on herself and her friends. With one small alteration, of course. So things are shaping up to be entertaining as our old friends become acquainted with some new friends with varying degrees of success.

Meanwhile, a beast of legend has escaped from his prison. Although his changed nature has delighted one of Equestria's rulers, what he brought with him may become an issue.

And by issue, I mean a peril.

Fun times ahead.

Cover art by this fabulous person.

Alternate Universe tag because we're pretending Discord was never reformed.

During a blissfully rare calm in the hectic storm of Ponyville life, a disturbance in the Everfree Forest goes undetected. After receiving a summons from the Princess, Twilight and her friends are led into a curious task, one that they find themselves ill-prepared to handle - managing their stallion double! As each of the girls meets their very own carbon-copy-colt, they learn that dealing with themselves can be much more frustrating than they first thought.

Annoyingly, irritatingly, intoxicatingly frustrating.

http://www.equestriadaily.com/2011/10/story-giving-love-helping-hoof.html