Much better. Just a few minor fine-tuning things I'll point out, and I honestly think you've got it. The improvement between this one and the last one is night and day, really good job!
Dragons, Hydras, and Nightmares were only legends until one of them landed on seventeen-year-old Iris Mjolnir’s house. As
the world became overrun by mythological creatures mythical creatures overran the world (Just switches from passive to active voice), humanity is was brought to the brink of extinction. With only her Maltese dog by her side, Iris faces the world alone, searching for her missing parents.
Iris can take care of herself. She crafts weapons and fights monsters ranging from bug-eyed Screechers to giant arachnids. But when a Griffin gets the drop on her, she’s helpless until a metallic warrior slaughters the beast by riding a lightning bolt onto it. Iris finds herself at the mercy of the Horseman of War who acts
a lot more like a disgruntled father than the master of all things evil. Turns out it’s for good reason; Iris has his blood running through her veins.
But War isn’t convinced. He gives her a proposition; do his bidding to prove her heritage and he might rescue her parents. Luckily, Iris won’t be alone. She’s got the help of the other three
“Spawns ” of the Apocalypse; a boy with blackened wings who fell out of the sky, a girl at odds with her own mind, and a long lost friend turned grim reaper.
There’s a war brewing in the near future (between _____ and _____, war is just a tad vague) and the Horsemen need soldiers. If Iris and her new friends succeed in proving their heritage, they will be perfect candidates for
their War's army. But, if they fail, Iris’ family will be left for dead, and there will be no one to defend the world against the coming onslaught that not even the Horsemen of the Apocalypse can face alone.
IRIS MJOLNIR SPAWN OF WAR is a 96,000 word, young adult, apocalyptic fantasy novel. It is a standalone novel with series potential.
Thank you for your time and consideration.
Like I said, just minor fine tuning. The word count might give you a bit of trouble, it's on the high side for YA fiction, but not unreasonably so. Good luck and happy querying!