Was sitting in a bus yesterday when I got this stupid idea. There are 6 elements of harmony and 6 infinity stones. Elements of Harmony are the supreme force in Equestria that can do pretty much anything from what we have seen. It wouldn't be terribly hard to write a crossover where the elements contain the infinity stones.

Hell, they even match with most of the elements.

Power stone - Magic. Knowledge is power, and Twilight does anything but lack power.
Reality stone - Laughter. It's Pinkie Pie. She does whatever she wants and the universe yields and then goes to cry in a corner.
Soul stone - Kindness. Fluttershy is the gentlest of souls.
Mind stone - Generosity. The creation of art is the fruit of the mind. Rarity knows this.
Space stone - Loyalty. Rainbow Dash flies though space with astonishing speeds.

Only one that kind of sticks out is Applejack and the time stone. It could be made to fit though.

I even came up with a short description for a story.

It was a typical day in Equestria. Well, it was until a blue turd in a jumpsuit stole the elements of harmony and shattered them before the bearers eyes, only to reveal 6 brilliant gems that seemed to overwhelm the reality. The grinning titan was about to grab the stones, but was interrupted when a portal opened next to him. And angry man with a glorious hair and a hammer rushed through and smashed the titan though another tear in reality, following him into the portal with an angry yell.

The stones, now free from the titan's influence began to fall. Twilight panicked and grabbed the stones with her magic, only for the stones to react violently and break free from her magic. Each stone flew towards their respective holder, and then there was only light.

The bearers woke up 3 hours later only to see extremely worried faces of the princesses. None of the bearers recalled how they ended in a crater 3 miles wide.

The bearers have returned to Ponyville, but something is wrong. Twilight is constantly having power surges which threaten to destroy her home. Pinkie and the Cakes are homeless after their house somehow turned into cake. Rainbow Dash keeps waking up in random places around Equestria, Rarity hears voices and Applejack swears she saw herself. Can the main 6 controls the powers of infinity before they destroy themselves?

Power= Twilight
Mind= Applejack
Reality= Rarity
Soul= Fluttershy
Time= Rainbow
Space= Pinkie

I'm doing a Marvel crossover universe with MLP and I sort of had this idea a while ago. I ran into the same problem as you, with not knowing where to place the Time stone.

Oh well.

I'm a long way off from the Infinity Gauntlet storyline, anyways. I'm sure I'll figure it out by then. :P

4406498 The time one is a bit tricky, but if we alter the holders a bit. As 4406478 said,

Power= Twilight

Mind= Applejack

Reality= Rarity

Soul= Fluttershy

Time= Rainbow

Space= Pinkie

It still works pretty well. Only thing I feel a bit unsure about is Rarity having the reality stone.

4406944 try Applejack for reality, and Rarity for mind. As for why you are insecure it's because... in fact here is my list of possible infinity stone.

The book in "Inspiration manifestation" countain the reality stone

The mind stone was part of Sombra's trap in "the crystal empire"

Trixie shown up with the power stone around her neck in "magic duel"

The time stone has not shown up yet but I think Star Swirl the bearded studied it at some point

The space stone could be around chancelor Neighsay neck

The soul stone is on the dragon lord scepter

5646689
too much awesome this is too good

4406405
Funny enough, I recently got a similar idea to include an expy of the Infinity Stones in one of my stories, only there are ten instead of six and the Elements of Harmony are one of them:

1. Darkness
2. Light (Elements of Harmony)
3. Space
4. Reality
5. Time
6. Energy
7. Chaos
8. Magic
9. Mind
10. and Spirit