Derringer

The Derringer is an Akafuji-branch tank, but when it opens its lance, auto-turrets pop out at their internal edges. They deal decent damage, and are brutally effective in farming. They are also okay at fighting, especially if the user can get up close. Like all Akafuji-branch tanks, the lance still deals damage when opened.

As the Derringer
You have very good attack and defence, so a speed build will make you almost invicible. And remember that your auto-turrets have their own FOV, so you can attack enemies from far, or close.

Against the Derringer
A Derringer is powerful, so even drones tanks won't be enough. Try a fast tank, like Propeller, Tri-Angle...    Bullet spammers can work if you're fast.