WMG / The Powers of Harmony

Libra and Hakumbele were the same pony.

It's commented that after Libra went into exile, he vanished into the Zhevra Flatlands. The Zhevrans, meanwhile, talk about how Hakumbele descended from the mountains to aid them against a great evil. So, it's easy to imagine that Libra showed up, had his Chronic Hero Syndrome kick in, saved them, and the rest was a result of Legend Fades to Myth.