Sorry to keep asking these questions but i wonder if anyone actually knows? kind of a double question what does the merovingian have against seraph, he calls him a traitor, In the short fight right before the "coat check" fight in Revolutions, one of the guards is seen calling him "wingless" and i have heard him called a 'fallen angel'.
now im aware that seraph is is a biblical allusion to the first of nine orders of angels, the seraphim. This allusion is also evidenced by the fire-like appearance of Seraph when Neo sees him in his coded form. The word 'seraphim' comes from the Hebrew word saraph meaning 'burning'.