An intergalactic space army called the star guardians are assigned to go up against the most dangerous army in the galaxy led by the charismatic and evil leader named Blade.

There is also a well known sci-fi book by Andre Norton called "Star Guard"

There's not much more I can add to the really good advice posted earlier. I would like to point out that your names are awfully close to two of Marvel comics characters: Guardians of the Galaxy and Blade. I'd recommend trying to come up with something more unique.

Hard to see a story here, unless you are "hiding the ball". (See Blake Snyder).

From logline.it guidelines :

? the Hero's function or role in the story (e.g. a mother, a cop, a scientist)
? the Hero's weakness and/or how it's overcome (optional, e.g. headstrong, timid, solitary, cocky, depressed)
? the story's first major event or ?Inciting Incident? (optional)
? the Hero's goal or main action in the story
? the obstacle(s) and/or the Antagonist
? the stakes (unless implied in the goal/obstacle)

Of the six listed, you have one: Blade.