When a aspiring rapper discovers his friend dead he wants revenge, but when he is blamed for a emerging drug war he must escape his pursuers.

2 stories doesn’t make one.
You have to find a way to melt together the story elements.
If you want to track the revenge story you have an active character, so you can drop the ‘passive’ character part.
To have a rapper as a main character is interesting, you should connect this element to something else in the story to build a more solid design. Mybe the music industry is involved in the murderer? Try to include some elements of the plot in the logline.