Elva

At first sight; The Twins are initially quiet, Innocent, and distrustful of those that are new to them. They all seem to be loyal and gentle with those they trust. However as the series progresses, they slowly show that's merely an ruse and that they are really deceitful, cruel, and manipulative characters with great observation and intellectual abilities. They don't care about anything or anyone else except their end goal and they will try to achieve it by any means necessary, even killing those closest to them.