Reign is a word name meaning ruler. (Perhaps a nod to Scott Disick's purchased British noble title?) Lil Kim put it in the middle spot for her daughter, Royal Reign.
Aston seems likely to have been picked for its most glamourous claim to fame. It's part of the name of luxury car maker Aston Martin, favored by James Bond. It's a relatively rare baby name—hasn't ever been in the top 1000.
Updated to correct middle name.