With Princess Twilight’s coronation as the new ruler of Equestria drawing near, Blaze and Roxy’s Legion of Doom have the bell and do their power play on Grogar! However, Grogar turns out to be Discord in disguise, but the rangers suspect and find out that the real Grogar is actually here! And if that wasn’t enough, the Legion now has both the powers of Discord and Grogar, and are now ready to unleash their unified might on both universes!
However, there is hope! Legendary Rangers from other dimensions have appeared and are ready to help the rangers and Mane Six in anyway they can! But when the battle of the bell is getting nearer, the legendary rangers will need help from an unexpected ally to help save the world! It will take the powers of all of Equestria, the Beast Morpher Rangers, and the legendary Mighty Morphin’, Dino Thunder, and Dino Charge Rangers that came before them to take down this horrifyingly evil legion! With weapons, Zords and new megazord combinations, the heroes will have the edge they need to defeat this evil horde with ultra-powered proportions that no villain has ever seen! Get ready for the ultimate Ranger and pony epic team-up this world has ever seen!

Continuity:
Beast Morphers - It would most likely take place after “Rewriting History” since Vargoyle was defeated by the Red Ranger, but before “Target Tower” since the rangers will have their biggest battle with Evox after this!
Mighty Morphin’ Power Rangers - Takes Place 24 years after “Rangers In Reverse”, but for Tommy Oliver, it would take place after “Dimensions In Danger” since he obtained his Master Morpher during that time.
Power Rangers Dino Thunder - Takes place 13 years after “Wormhole”, but for Kira Ford, it would take place 12 years after “Once A Ranger”.
Power Rangers Dino (Super) Charge - Takes place 3 years after “Here Comes Heximas”, but for Koda, it would take place after “The Poisy Show” after his team up with the Ninja Steel Rangers.
Power Rangers (Super) Megaforce - Takes place after “Dimensions In Danger” and after the Street Fighter Wars movie, since Gia Moran will be appearing in this as well. However, none of the Megaforce/Legendary Zords will be used.
My Little Pony: Friendship Is Magic - A huge rewrite of the penultimate season 9 closer, “The Ending of The End”, so most of this will probably not be canon.

Also, in this rewrite, Cozy Glow gets reformed and becomes a ranger, and there will be no Cozy genocide. Only Tirek, Grogar and Chrysalis will get turned to stone.

I don't own anything. MLP & Power Rangers are both owned by Hasbro.