Ein & Eins

I drew this for a request to commemorate reaching 286.000 hits on a web site. The request came with the following settings:
The two girls are actually the same pricess, the one on the left is a holy knight.
The red pattern on the armor of the girl on the right pounds with light just like blood, and her armor moves as if the evil eyes on it were alive. By putting on such an armor, the princess turned into a dark knight who likes blood.

The knight on the left is Ein, and the dark knight on the right is called Eins.