User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-3965848-20180516212727/@comment-32573280-20180516233303

My guesses (The ones before the "or" are 1st choice while the ones after the "or" are 2nd choice):

Rias - BM Sairaorg or Kiba

Asia - BM Fafnir My reasoning for him is that his greatest treasure is Asia's smile and she is happiness when she is with Issei so why not support this my being one of Issei's best men.

Akeno - BM Tobio

Koneko - BM Gasper or Kiba

Xenovia - BM Kiba or Saji

Irina - BM Dulio

Ravel - BM Riser

Kuroka - BM Vali

Rossweisse - BM Vidar Him choosing Rossweisse to be his bride was a ploy by him to get her together with Issei.

Le Fay - BM Arthur

Elmenhilde - BM ??? I have no idea who the best man for her's could be in my opinion Gasper not really close to her.