Well You’ve come accross a fundamental problem in realtime rendering, especially in deferred renderers such as UE4.
If you have nested or partially overlapping meshes you can try and set the transparency drawing order manually to resolve the, but in a skeletal mesh where you can probably see all of its sides while it moves you’re gonna have to use a dynamic method such as the one alreday linked by .
True OIT (order independent transparency) is not implemented right now in UE4, and as every solution out there has drawbacks of some sorts, i think it will take some time until the epic guys figure out how to do it in an elegant way.
In the meantime you’re gonna have to use hacks.