I liked it! If I could make a recommendation, I think your sentences can be a bit redundant at times.
EX: "The creature in front of him, which happened to be a rat-like humanoid as well, nods satisfied."
You could probably have just said "The other rat-like humanoid nodded, satisfied." and it would've been just as clear and saved you some words. That's just one example, its definitely a pattern in your writing, but it's not too detracting. It just eats up a lot of words in such a small format, and sometimes it can slightly throw off the flow of what is otherwise a cool story.
Likewise,I feel like you could've given the captains death a little more focus. Maybe set the scene of the Rat-Captain reviewing his troops at the funeral for the prior one.
Other than that, I very much enjoyed the story. I very much appreciate a story in the vein of Frankenstien, but with the created being better people than the creator! Keep up the writing!