The black tattoo marks around Anji's eyes are from Tsubaki's ashes.
Sanosuke: Your eyes look different than before Anji. They don't look like the eyes of a killer. That's the way it should be, you can go back to being a gentle monk again and start over from scratch.
Anji: (To Tsubaki) I don't deserve such kindness.
The Japanese title of this episode is:
The Focus of His Gaze: Anji's New Reflection.
When Sanosuke and Anji's fists collide in the manga Sanosuke learns a new technique called the Sanjuu no Kiwami. This is when he snaps all five fingers out and sends the Futai no Kiwami back at Anji, although, this technique isn't mentioned in the show.
Anji's past life as a monk is revealed while he's fighting Sanosuke.
Anji: Namu Amida Butsu
"Namu Amida Butsu" is a Buddhist prayer chant.