Rainbow Dash has a freak accident while performing a Sonic Rainboom, and awakens to find herself in a strange new world, with strange new abilities.

Avengers and My Little Pony crossover.

Image Credit goes to Alienfirst : Link

This story is a sequel to The Dresden Fillies: Strange Friends

Almost a year has gone by for Harry Dresden since he left Equestria. He'd have written, but between saving his newly discovered brother and destroying a scourge of vampires he's been a little busy. Then out of the blue he receives a strange letter from Twilight asking him to return. With no cases at the moment he eagerly accepts, but his friends aren't the only ponies expecting him. There's been a lot of rumors since his last visit and some ponies aren't too keen on seeing him come back.

A sequel to The Dresden Fillies: Strange Friends.