User blog comment:Lia Schiffer/397: Edge of The Silence/@comment-1243139-20100329145040

Think old guard, Shinji didn't recognize Isshin's reiatsu and Urahara referred to him as senpai or some term of respect implying that Isshin was a captain around the the time of Ukitake, Kyoraku, Unohana and Yamamoto but I don't think Royal Guard would suit a guy like Isshin and definitely not being the King of Souls good plot twist but cliche'.