Thanks for the welcome and that captain is Hitsugaya (you can see the "+" symbol on his back), besides, some chapters earlier you see the girl sternritter is the one who stole Komamuras bankai, The hollow mask - looking guy is facing Soifon, you already know who stole Byakuyas and the last dude is facing Hitsugaya, you can see them all here: http://www.mangareader.net/bleach/497