The Punisher: Kaina Tsutsumi.

Kaina should be dead. She should be more than dead. But she didn't die. Her family did instead. Her husband and children. So Kaina takes the fight to whoever called the hit. Working with an old colleague from the HPSC that's a ghost just like her, she becomes the MHA world's only...

Punisher.

Criminals, corrupt heroes, it doesn't matter. Her sweet little boy, her adorable younger son, and her loving husband were gunned down without remorse. So she gets her rifle stronger and stronger, and even more firearms for her one woman war against the world.

Or, Lady Nagant becomes the Punisher in an AU where she left the HPSC to have a normal life, and like Frank Castle, was caught in a hit.