So i picked a theme for the story.

Four centuries ago Equestria was founded, then came the Gryphon Kingdom. These two lived peacefully with each other until a new relic was discovered in a cave at their borders, this new discovery lead to all out war between the two factions. Gryphon against Pony, the war was catastrophic; each side losing more than 200,000 units in their selfish struggle. Canterlot won by using their powerful spells as a last resort, ending the great war. Now it is called by another name: The Rainbow Gate War.

Now it a century later and all is at peace once more, families still mourn the fallen, Princesses who participated are buried in their castle gardens, where they are guarded. None have survived, but one who could only stand by and watch as each faction went at each others throats for this relic. And this princess is Twilight Sparkle, the element of magic and friendship. She sees the relic as a curse and feels it must be kept out of anypony's hands.

So she decides to act on that feeling and has it hidden away forever, but that action will bring about another war, the same is about to happen again. Those seeking this relic finally find it, but Twilight foresaw this and sends an army to dispose of them, she is tired of it all, each time a new threat would come seeking it, Spike her guardian dragon protects her and helps her in her goals to restore what is broken, Harmony.

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Here is an image of Twilight and spike i found on Deviantart:

So to put it simply, this is one of the possible futures of equestria. A war ridden world, where anypony is at risk. A relic that can cause this much chaos can lead to many conflicts.