Did Thresh kill Senna, or just put her in his lantern. Plus if he did kill her then is Lucian just aimlessly hunting Thresh for revenge, or does he have a plan to get her back.... Or will he just take the lantern so she can be at his side? Because I'm kinda getting that vayne feel of "this one thing happened, so now all y'all gonna die".
Thresh did both, since the act of having one's soul removed pretty much kills them. Originally Lucian thought she was just dead, but with the recent revelation that her soul endures in Thresh's Lantern, his goal is to free her. This then leads to the plan of killing Thresh and destroying the lantern.
Which leads me to the natural question: why does Lucian not just lure Thresh into an ambush and shoot the lock off the lantern? Even if Lucian should fail the first time, he could just run away and try again later, perhaps even trailing Thresh and trying again every few days until finally landing the shot.
The only bad outcomes could be:
