Skin concept Idea: Reverse Ionians
Basically a Skin line where the good Ionians are bad and the bad Ionians are good.
The face figures being Syndra and irelia. Imagine Syndra being clad in red and blue, with bright colours to represent her vigor and goodness, whereas Irelia is clad in Black and purple with teints of a deep, blood-red and having an angry face expression.
The same could be done with Zed and Shen and other Rivalties within Ionia such as Udyr and Lee Sin.