Kanaya, I am loving where you're going with this, but that will absolutely not kill him. You need to finish the job!
To be fair, no one really understands what's happening to Gamzee. Kanaya probably doesn't want to execute a guy who, up until an hour ago, was just a harmless stoner.
Kanaya refrains from ripping Vriska's throat out, which tells me she does not know about Tavros.
Killing Vriska might prove rather difficult, in any case. That would be a very unlucky break - and Vriska doesn't do unlucky breaks.
Nice Argument
Unfortunately
It Looks Like Your Magic Has Run Out
Now
You Want An Auspistice?
Then I'll Give Your Legs Some Space From Your FUCKING TORSO









