The similarities could include similar character archetypes, similar use of visual cues for emotions or plot points, and similar overall tone and mood. Plus, the way the story builds tension and resolves conflicts might have some resemblance.
The Black Lagoon manga is not ongoing anymore. It wrapped up some time ago, but it left a lasting impression on fans with its exciting storyline and memorable characters.
The ending of Black Lagoon manga is quite intense. The main characters face some major challenges and the story wraps up with a mix of resolutions and open-endedness that leaves room for interpretation.