Unoriginal and uninspired.
Honestly, I expected more from a crossover with so much potential. And this... doesn't deliver.
The start of the fic is bland and uninteresting already - the team is stranded in the Everfree Forest (the default spawn point for HiE insertions), and someone brings them to the town. So, to cover up for that, we get INSTANT ACTION AGAINST A NEW (BUT OLD) EVIL!, where it shows how crazy awesome the newly-ponified BLUs
are while making all the MLP cast, even the Princesses, almost entirely useless. Another thing is, there's no conflict between the two worlds' characters except for the Equestrians finding the BLUs creepy and brutal. But that's not the worst: what is
is how much the author shoehorns cheap grimdark on the BLUs' background. I stopped reading after a very badly written sob story the Spy tells about his family.
Good grammar doesn't save a bad fic. Disrecommended with both thumbs down.
EDIT: Added a missing parenthesis.