Hmm.. it seems it's kind of her xml2 chain lightning. Ok then, I'll "experiment" that next days. Thanks for that point. 
EDIT: I see there are three types of "adds" on her Lightning power: 1. Lightning Stryke (her normal lightning bolt), 2. Chain Lightning (the lightning link from the main power) and 3. Legends Lightning - WHAT THAT MEANS? I need to know what Legends Lightning from xml1 represents.. Please!
In XML1 all the powers had, hmmm 3 stages (or something like that, I don't know how to call that, lol), for example, Lightning Strike was the basic power, then you upgrade it to Chain lighting that added more strikes as a chain (the one that is in the video you posted before) and then the highest version of the power is Legends Lighting that affected all the foes on the screen (or something like that, honestly I don't remember)
I think you should check the 2nd version of the power (chain lighting) since is the one that has the chain that you want.