"Maria vs. Tock and Assassins" is a battle that occurred in "The Grimm Reaper".
Tock set off her stopwatch to 60 seconds and tells Maria that this will be her last 60 seconds of her life. Tock then activates her Semblance and attacks. Maria has some difficulties fighting her multiple opponents and her Aura is depleted. However, this does not stop her and she combines Life and Death into a single weapon. She manages to defeat three of assassins, but she has a hard time battling Tock. Maria lets her guard down as Tock uses her metal teeth to break her weapon in half, headbutt her mask and finally slash out Maria's eyes.
Tock deactivates her Semblance. Maria attempts to shoot her blind, but she misses. Tock tells her the reason why she is hunting people who posses silver eyes: because she was ordered by her master. However, she considers of sparing Maria's life since she no longer has eyes anymore. Maria throws her broken weapon at her, but misses. Tock changes her mind and decides to kill Maria. Maria manages to activate a switch on her weapon and uses the other weapon that she threw earlier to stab Tock in the back, before decapitating her.