I don't know how or with what to frame this thought, so I'm just gonna leave it here.
If Ken were a Virtue, he could be Virtue—Love.
One time I came across a theory that Ken might be a former Virtue who betrayed everyone and got taken out. And it said that Ken would've either been Kindness or Patience. But honestly, Patience clearly doesn't fit Ken (and besides, it's already taken. Sure, in the past he could've been different, but hey—let me have my little theory here), and Kindness... Well, Ken's a good dad :-). But that said, if you were to assign Ken a Virtue, Love would suit him. It can be both a pure feeling and a clear motivator for bad actions. Ken's obviously not a good guy, and not everything about him is straightforward, but we do see him caring for his kids (he praised Breadhead and fussed over him, and he protects and looks after Mel). But unfortunately, that's about where my arguments for "what kind of Virtue Ken would be" come to an end... Yeah... Kinda awkward, honestly, but I finally said it...













