epi 154 erza said this is our answer & during the Erza & kagura fight erza said: Simon died because of my weakness but what does it mean?

Oh! I think I know this one.

Erza's weakness is pickles and Simon died 의해 eating too many pickles. Therefore Simon died because of Erza's 간물, 피 클 weakness.

당신 must have not seen that arc. Bruh I haven't seen Erza and Kagura fight yet and I know why she said that. Watch everything in order and you'll understand what references the characters make.