Spriggan (ONA)

Both have a concept about civilization 

Both shows revolve around venturing into unknown territory, in Spriggan, its for Relics of an ancient civilization whereas in Gunjou no Magmell, it can range from obtaining rare species of a plant to high selling organs of animals for sale in black market.  

Both anime have a similar military themes about organisations that aim to keep pandoras box closed while focusing on a young overly capable character. 

Gun-based action dominated the early 2000s action anime genre, especially with the girls with guns trope. The industry might have moved on, but you can still find new gun-based action. Spriggan and Jormungand have different stories, but are gun-based, violent, action anime series with paramilitary organizations. Sometimes a simple story with violence is the best approach.  

Violence. Action. Paramilitary organizations. These keywords are sure to resonate with you. Spriggan and Hellsing try to deliver on this content to various degree of success. Although Spriggan is not a finished anime, it will likely share a similar structure as Hellsing. The first part of Hellsing is episodic before incorporating an overarching narrative into the storyline. Hellsing is definitely the better anime with its cooler characters, but Spriggan does have its own appeal with its fluid animation. 

Spriggan and Black Lagoon can be summarized as episodic, action-packed, violent series. With episodic series, the A plot is limited to a single episode and is intended to showcase the characters whose arcs become the B plot. Everything therefore rides on the characters and the setting. Black Lagoon is highly regarded for its characters and setting. It has depth that elevates the series from what could have been a regular action series. Spriggan has very fluid animation, which is very important for an action-packed series, but it struggles on the characters and the setting. It might not be a remarkable series in this genre, but it should satisfy you when you're looking for a new violent action anime.  read more 

Oh baby that's the good stuff. 80s shlock at it's finest but with a new coat of paint. I can't possibly see why you wouldn't watch both of these shows right now unless you're too young to enjoy something that's completely stupid and insane.