This Seeking Tech guide will explain how you can unlock the Ectoplasmic Slasher trophy in Sly Cooper and the Thievius Raccoonus (2024) on PS4 and PS5.
You can use the following video as a reference:
For the first step, make your way through A Grave Undertaking until you get to the arena with three totems.
Afterwards, run around until you get at least 5 ghosts chasing at you from behind. You can then attack them with one strike to unlock this trophy.