What is the significance of the knightmare sequence in batman v superman?

The only entity confirmed by the evidence is Superman. There is no documented reference to a knightmare sequence, its role, or its significance within Batman v Superman. Without further sources, it is not possible to describe the sequence or its impact on the film’s narrative. If you seek details, additional reputable references would be required. Until such evidence is found, any discussion of the knightmare sequence remains speculative.