Yup, time to answer some questions~!
Blizzard-dream: Robin's dead. Or is she...? We never actually saw her dead body, now did we? What's going to happen to Death?
She's definitely dead, unfortunately, or else Barb would have had to reason to bother Blight about getting Belladonna, right? Poor Robin never had a chance, although she refused to fold, surprisingly. As for Death, he just needs some practice. Before now, he's always had someone to mooch off of (as we might find out soon), but he's on his own now and has to fend for himself and support the Clan. He just needs some time and training to get the hang of things.
Hiddenfilly: Does Northstar seriously think he can win without StarClan's help?
Sadly, yep. To him to seems as if StarClan turned their backs on him. Not only that, but StarClan hasn't done much for the Clans, at least in his eyes; they didn't warn the forest Clans of FrozenClan's plans, and they didn't tell Frozenstar that his son was planning his death, nor did they save Brackenheart and Birdpaw, the only two cats who mattered to Northstar when he was young. To him, StarClan seems almost powerless; if they had power, why let a medicine cat die? Why let Northstar seize power and destroy the forest Clans, only to lose his power to Crowtalon (and eventually Lion)?
Crowstorm: So anyways, why was Northstar so mad?
You didn't miss anything, don't worry! Northy has problems. He's angry about his part in Rabbitpaw's injuries (and perhaps death) as well as how Rosedapple is bent on ending her life, and he's conflicted about some other things that we'll eventually see.
Lynxeye: I wonder where Stoneheart was when Graywing died?
Stoneheart was there, but just as shocked and shaken as everyone else...Graywing was actually his sister! He was too overcome by emotion to take control. Northstar wasn't close with Graywing, and saw her as the reason for Rosedapple's grief, so his emotions weren't as strong.
I'd also like to say a few more things:
First, it really surprised me how much hate Lightstar/Graywing have received. Males turning on their female mates isn't that uncommon, even in canon (Spiderleg/Daisy, for example, or the countless toms who moved on after their she-cats died; Crow/Feather, Fire/Spotted, Gray/Silver, to name a few). Lightstar is, at heart, a good cat. He's a little young to be leader and overtaken by emotion easily; he lacks responsibility. Graywing is gentle, but very emotional as well, and although her loyalty to StarClan was great, she always was true to StarClan. And, as her last words showed (kinda) she and Lightstar never actually meant to hurt Rosedapple. If Lightstar had known Rosedapple was pregnant, he would have never continued his affair with Graywing. Unfortunately, by the time Graywing realized she was pregnant, it was too late. Then, there is PeakClan's society; StarClan is a distant thing to them, a force outside of their daily lives. Breaking the warrior code by mating with a medicine cat isn't shocking or strange to them like it would be in, say, RiverClan. It just doesn't matter to them; Graywing just has a little tougher time doing her job, is all.
And then, new reader Queen of Pens brings up some excellent questions. First, Northstar could still easily kill two cats, even after running. He was born in the mountains, remember, so even though his paws took a bit of a beating, there wasn't nearly as much damage to them as there would be to a normal cat. Also, he has always been a good runner; it takes much farther to tire him out than with normal cats. Finally, he did have a bit of time to rest. The patrol that found him and been moving constantly trying to find him, whereas all he had to do was sit and wait for them, allowing himself to rest. And then, about Slaughter: If you haven't found out already, Slaughter isn't a terribly important character, merely a stepping stone to the true antagonist, Lion. Lion is the more compassionate, emotional character you were thinking about. Slaughter is a bit flat, but it's intentional; he's a stereotypical "for the evulz/for the power" villain, and while he's scary, the capabilities of revenge-bent Lion are much more terrifying, simply because he knows right from wrong and chooses to ignore it. Also, he doesn't much care for Toxin. She looks very much like her mother; Slaughter didn't mate with her mother for love, merely power, due to her heritage. Toxin's mother managed to escape him, fleeing with his other daughter. This fact - that he didn't completely control her - has caused him to hate even the thought of her. Toxin's resemblance to her mother stirs up that hate, and he knows it clouds his judgment, thus he sends her away to help him focus. Also, he couldn't have known it would/could be suicide on her part; she's highly skilled in battle, and in his mind any cat of his kin should be able to kill three she-cats at the very least.
Next chappy is about Nightshade, guys, stay tuned~!