Just thought up these as well.

Enemy Suggestion: [url=http://img2.wikia.nocookie.net/__cb20120218112103/blackrockshooter/images/e/e3/Hooded_figures.jpg]Rogue Other Selves[/url] (They are Other Selves of different people, just like how BRS is the Other Self of Mato Kuroi. Yet, these Other Selves are undeveloped, and thus are unstable and left without the connection between their human selves.)

Enemy Suggestion: [url=http://umineko.wikia.com/wiki/Black_Battler]Black Battler[/url] (The embodiment of all of the theories that mark Battler Ushiromiya as the culprit behind all of the games. Due to this "theory embodiment" being very strong enough to exist as a physical being, Black Battler appears normally as the [url=http://keikakudoori.files.wordpress.com/2010/05/ushiromiya-battler.jpg]real Battler Ushiromiya[/url], but once either found out by the Red Truth/Blue Truth or even being "warped" in the MetaWorld by a witch, Black Battler would then appear with blood-red eyes and a black suit in contrast the white suit that the real Battler Ushiromiya wears. Black Battler isn't a force to be reckoned with, possessing very powerful "concept-altering" abilities that rely on the Red Truth, Blue Truth, and even the Purple Declaration.)