Hey there! I decided to check out your story and give you a review, and I'm glad I did! Lucario's one of my favorite Pokemon, and it's always good to see an interesting story about one.
So far, I've only read the first two chapters, and I can tell this is going to be a good story. Lucario himself is an interesting character, since he used to be human and yet doesn't feel any connection to the Pokemon he meets. Having him run away from Piplup, leaving her to the mercy of Brendan was a great choice to make as a storyteller. In that scene, you showed that Lucario isn't a "always do good for others" hero, and will make decisions that seem selfish in order to protect himself.
A quick tip I can give you is to just double-check your punctuation in your dialogue. In some places, you're missing punctuation. In others, you have the wrong one. It's really just a tiny thing that, if you fix it, will be an improvement to your story.