About the other death ends, he mentions how he wanted to watch us die. To 'strip himself of his last Humanity' or something like that, even though he hesitated. I'd imagine he'd just carry out his plan as usual no matter what. And the light is just the fire surging in, I assume, it seems to be coming from there anyway.
I was also curious on how exactly a random flame started- I'm assuming Ray started it. Double is too... tense around Ray to risk it(valid even if he's a prick). And Ray was EXTREMELY quick to saving us at the balcony, even if he has powers- we know it still takes time given by how he carried us away from the Crawler. I remember he attacked Luke(Blaze) and the social media said Luke was fine but... if there's anything to learn, don't trust PR. I bet he really did kill Luke, took his power, and he set our place on fire so he could make a decision based on our choice- be our Hero, or let humanity die off.
