Hey Mark! Have to say that I'm in love with the "cosmic horror" direction of Innistrad. Quick question: can you elaborate a little bit on how "eye for an eye" fits into White's pie slice? I love understanding color philosophy and eye for an eye feels closer to Red.

White is big on equal treatment and is the color of rightful vengeance. Eye for an eye is an idea that straddles White and Red.

I understand nahiri being red. It's impulse and emotion. Why is she white though? She's risking destroying an entire plane of people for revenge on Sorin, and she thinks her plane is dead so she isn't even doing it to save her own plane in some collateral damage way. Isn't white the color of balance, duty, the greater good, and things of that nature?

She is using white tools, not trying to achieve white goals. There is a bit of “eye for an eye” mentality which dips into White.

If hybrid mana cards have to be doable I'm both colors, is Boros Reckoner an egregious color pie violation or can white do direct damage sometimes?

White has what we call the “eye for an eye” mechanic where it can damage things that damage it in equal volume.