Senna did not find Cern. 

This is because Cern found Senna. 

Appearing from nothing as she was wont to do, the God with the appearance of a child revealed her presence before Senna after the latter had been walking around for a handful of minutes. While one would ordinarily expect a patron God to be annoyed or concerned at Senna's reckless attack on Zhan in the Labyrinth, Cern seemed to be neither of these. 

"Ha! What you did in there, shooting the Floor Guardian and then just bailing, classic!" Cernunnos giggled furiously as she appeared in front of Senna, walking backwards with her slender arms crossed behind her head. "You're great, really. Okay, okay, so before you say anything, let me guess: stat boosts? Well, lucky you! Since you encountered a Floor Guardian, you not only get a status update, but you also get my second-order blessing! I won't deny that the way you screwed over that Ares boy like that helped you out in earning the blessing, though~"

And then Cern gave boostos.

"...oh, right, I should probably explain what a Floor Guardian is, now that you've encountered one. Eh, I'll just add it to the Lexicon."

[center][i][Key Terms: Floor Guardian has been added to the Lexicon.][/i][/center]