 If you liked
Casshern Sins
|
 ...then you might like
Kiseijuu: Sei no Kakuritsu
|
Both series are slightly existential and cover heavy themes, both deal with the survival of humankind, and both contain supernatural elements in a semi-realistic world. For similarities concerning the main protagonists, both end up in situations where they must unwilling fight in order to live, both are condemned by almost everyone in their lives once they know the truth about who they really are, both have problems with their "girlfriend", and both have a few metal breakdowns throughout the series.