Shaxs' vision of the Battle of Tempasa
The Battle of Tempasa was a large-scale confrontation between the Bajoran Resistance and the Cardassian military near Tempasa, during the Occupation of Bajor. Part of the battle involved a bomb that the Cardassians had planted in a Bajoran artifact.
Shaxs was a participant in the conflict. In 2382, he experienced a vision of the battle wherein he had to fight and defeat the astral projection of his unresolved rage, which manifested as a twisted negative version of himself as well as the reanimated bodies of the fallen Cardassian soldiers. (LD: "Upper Decks")
The battle is likely a reference to the raid on the Cardassian base in the area by Kira Nerys and the Shakaar resistance cell that was previously mentioned in DS9: "Ties of Blood and Water". Shaxs was a member of that resistance group during the Occupation.