Different destinies for different ponies. The Ultimare's started off very differently without a sonic rainboom... Living in the big city they had very drastically different lives. And yet, they all gained their cutiemarks from a singular focal event.

Each of these ponies are drastically different from their Canon counterparts.
Stardust Nova - Twilight Sparkle "To Kill a dragon"
Ink Blot - Pinkie Pie "The stress of a smile"
Ivory - Rarity "Diamond in the Rough"
Sparkling Cider - Apple Jack "Burning Beauty"
Prism Wing - Rainbow Dash "Potential Never Wasted"
Cottontail - Fluttershy "Inner Animal"

Note: I would have a cover photo, but I could never get the artist to respond to me, so for now there is nothing...