I need some pointers for my story (no spoilers)

So I'm working on this one story; The Adventures of Thunder Strike and Ink Blot. I need a few pointers for it.

First, a quick summary. It's told mostly from the perspective of my OC, Thunder Strike, along with his best friend, Ink Blot. They both live in Canterlot, Thunder as a royal guard and Blot as a news reporter. The story follows them going about their business, living their lives, and meanwhile the mane six are having their adventures in the background, with their paths intertwining every now and then, particularly in the climax.

The boys befriend a few of the other soldiers, fight in a conflict with the changelings, have some disputes with Princess Celestia and her loyal followers, and pursue relationships with their two marefriends, Trixie and Cheerilee.

Now without giving away too much, the plot/meat of the story revolves around this path that Thunder Strike is following to achieve greatness. There are some very dark turns along this path, and a lot of the characters turn out to be really dark with shady intentions.

So here's what I need help with: First is the title. I don't think this is a title that will really grab any reader's attention. At first, I had chosen this title because I wanted to make out Thunder to be a hero. I've thought of a few alternatives:
-The Knife that Cuts Deepest
-Until The Sun Goes Down
-The Brewing Storm
-Power is Magic
-The Storm In the Shadows
If anyone else is willing to offer any more ideas, I'm all ears. I'm starting to lean towards the first one.

Next is the characters to list. When I first posted here, I did not know you could only have 5 characters. So OC is a definite. Who else to choose? I'll list the canon characters that have major roles in the story, and what those roles are:
-Mane Six: Having their adventures in the background. Thunder and Blot take notice of them every once in a while. Occasionally their paths intertwine. They start a radio station the Thunder, Blot and their friends listen to, and Blot gets to hear their friendship reports. Eventually, there's this story arc where Applejack is framed for a murder, and Thunder is tasked with arresting her. Twilight is the most prominent of the six. At the climax, they do something that really puts a dent in Thunder's plans.
-Shining Armor: Captain of the guards. Thunder's superior. Eventually, the two form a kind of friendship, Shiny promotes him to higher ranks. They are often in good humor with each other. Their views on the guards and Celestia's orders tend to clash sometimes. Shiny has a major role in the climax.
-Princess Celestia: Plays a major part in Thunder's path to greatness. Thunder does not approve of a lot of methods by which she rules Equestria, and tends to argue and clash with her at times.
-Queen Chrysalis and the changelings: Assault different areas in Equestria that the guards and wonderbolts have to thwart. Chrysalis herself does not appear much in the story. She does have an OC sister, Asphyxia, who often fights Thunder. She can be considered Thunder's archenemy, and a major antagonist in this story.
-Trixie: Thunder's love interest and marefriend. Not exactly sure how much she'll be in the story yet, although she later does become a big part of Thunder's path to greatness.
-Cheerilee: Ink Blot's love interest and eventually his wife. Will probably have just as big a role as Trixie, though not sure how big that will be.

Last is the summary. Not sure if what I put will really grab the reader's attention either. I think it's pretty sloppily put together too. If anyone's willing to give me tips on one to add to it or how to polish it up, I'm all ears.

So can anyone help me? Anyone got any ideas for any of these 3 things?