Thea's belated side-effects to the Lazarus Pit have really come into play this season, not always for the best. It wasn't done all that well through the opening episodes, and then was sated temporarily after she killed a couple of assassins in Nanda Parbat. It's back again though, and it's going to keep coming and going because the only definitive way to stop it is to kill Ra's al Ghul, and you can't kill what's already dead. However, she has a plan, which involves the intriguing development that Damien Darhk's powers don't work on her. There's only so much ground you can cover with Thea's bloodlust coming and going, and the resolution is now the most interesting part, so it'd be good to get to that sooner rather than later.