Mahou Shoujo Tokushusen Asuka

Both have a close-knit group of people fighting against some evil. Both have a close relationship between the "main character" and a friend. 

Do you like yuri? Do you crave violence? Especially with guns? Well do I have the show for you.  

Both are dark twisted magical animes that explore concepts like death, ptsd. 

Both shows are "Dark Mahou Shoujo" exponents, showing us "magical girls" in a really obscure scenario that involves death, blood, suffering, and psychological damage to the main characters. The girls are in real risk to die and villains are genuinely evil, also, some "allied" characters are not particularly "good ones", having some psychopathic or evil attitudes. For both shows being a magical girl is more a curse than a gift. also, yuri implications  

Both shows revolve around a group of teenage girls that are trained killers. In "Magical Girl Spec-Ops: Asuka", they work together most of the time, while in "Akuma no Riddle", it is more of a survival game between them. The main characters Asuka and Tokaku are both kuudere characters, who don't really show their feelings, but care deeply about the secondary protagonists. Both anime have a dark setting and a lot of violence, but "Magical Girl Spec-Ops: Asuka" is in some cases more explicit and even disturbing. 

Both of them use very realistic approach when it comes to combat, characterization, society, social issues, and violence. Both of them have very realistic use of "magic" in real life. 

Both of these series integrate fantasy/magic well with modern military equipment/structure. Highly recommend if you like to see the military actually be useful in a fantasy setting. Also, piles of cute girls!  

Teenage girls in short skirts with lethal weapons fighting against evil. a bit school life and Girls Love subtext. special abilities involved! All Hail Short-Skirted Heroines! 

Goodlooking girls in cute/sexy uniforms/costumes wielding weapons/using supernatural powers fighting against evil and protecting the world. The difference is, in Mahou Shoujo Tokushusen Asuka, the girls hide their identity as magical girls in public. While in Ange Vierge, the girls' true identity as super heroines are not covered. Its time for the girls pick up their weapons and save the world! 

Goodlooking girls in cute/sexy uniforms/costumes wielding weapons/using supernatural powers fighting against evil and protecting the world. The difference is, in Mahou Shoujo Tokushusen Asuka, the girls hide their identity as magical girls in public. While in Schoolgirl Strikers: Animation Channel, the girls' true identity as super heroines are not covered. Its time for the girls pick up their weapons and save the world! 

High school girls fighting with lots of good gore and big titties. 

Although in a gritty magical girl setting, the general synopsis is fairly similar. Both worlds suddenly have a mysterious gate that opened up in the human world, bringing in fairies and monsters alike. Humans and supernatural creature begin orchestrating crimes, and there's a force to oppose them etc. 

Both have quite a lot of action, violent battles, busty characters in fancy outfits and cool music. Produced by the same studio. 

The military recruits magical girls to fight monsters from another world. Fair amount of fanservice as well. 

Both of these shows are very dark, violent and bloody also they are both about magical girls. 

Same director, same feel of "dark" dramatization of otherwise mundane dialogs, events, and facial expressions. 

Mahou Shoujo Tokushusen Asuka in many ways feels a lot like a yuri version of Seikon no Qwaser without all the boob sucking. 

To start off, both of the main characters are extremely similar. They are both haunted by their past with loosing comrades/friends. They both find new strength in protecting their comrades/friends. Both shows contain military elements, with secret operations and protecting the world from a supernatural enemy. Both of the shows have girls from different countries but they eventually end up altogether Japan. The only real difference is that one focuses more on magical girls and the other focuses more on girls with fighter jets.