Cassandra Nova/The Mummudrai
With giving Cassandra Nova Empathy Jean Gray made the biggest mistake in her life, She gave Empathy to a being that could never ever deal with it as a Mummudrai is not meant to have Empathy thus Cassandra has gone mad to deal with it.
Changing her powers she now has two forms the first is that of Cassandra Nova a kind creepy old lady who talks to eerily sedate people about issues like bottled up emotions and psychopathy she reveals to the world in subtle ways that she had found a way to suppress the darkness within it only manifested as a way to protect her and her friends. (Think a Marvel Version of Bray Wyatt only with powers) She has been passing the gift of Empathy to people who needed but it has been driving people insane breaking them because they did not get Empathy in a positive way. She calls up friends that represent various people and that they their own powers.
The Mummudrai is a unstoppable monster those facing it quickly realise that it can not be stopped it uses devastating power to break those in its way.