Just something I thought about and wanted to point out:
Some Battleborn have lore challenges that require them to play on the same team as another Battleborn 5 times, or kill another Battleborn 25 times. Some of the lore challenges to play with a specific Battleborn go both ways, such as Phoebe and Marquis, Ghalt and Mellka, Miko and Kelvin, and Galilea and Ambra. But Ambra is the only character who is required to be killed by more than one Battleborn, on the same team as more than one Battleborn, and even killed by AND on the same team as one Battleborn.
Deande has to play five games with Ambra, Alani has to kill Ambra 25 times, and Galilea has to do both, thus making Ambra the most popular Battleborn and the only one with a connection to Battleborn from two other factions.