One:
The mission quickly got out of hand. All it took was one direct hit to Casshern's chest - an extremely lucky shot, of course, but for the sake of the sample, it hit - for his eyes to suddenly start glowing blue, and his facemask to close. All of a sudden, Casshern's body contorted in an inhuman way as he stood back up from the hit, the 'wound' barely a blackening of his white combat suit, as Casshern seemingly vanished into thin air. It wouldn't be until the enemy mech looked upwards did Casshern rematerialize, landing on top of the mech's head in one deft motion, Casshern's heel colliding with the machine's 'temple' with a thundering chrash, denting the head so badly that its internal components came out of the other side. Casshern then ripped the machine's head off, diving straight into it through the gaping 'neck', and what followed was a disgusting scream and 'gurggling' noise over the comm system as Casshern was clearly mauling the pilot with his bare hands. Shortly after, Casshern bursts through the machine's chest, covered in blood and human refuse.
He's now staring at you, trying to determine if you're a threat. Unfortunately, that's the side-effect of his Berserk Mode: A highly flawed IFF system.
Two:
Casshern can be seen post-mission in the lounge of the White Chalice, with two books. The book, open on his lap, was "Beyond Good and Evil" by Friedrich Nietzsche. The second book?
THIS shit. Yeah. He's not adjusting well to his new emotions, or his ability to feel guilt for his actions, or the knowledge that killing Luna was causing almost an entire continent's worth of humans and robots to suffer needlessly.
When you approach, he looks up at you, for a second. He then looks back down, not in much of a talking mood, but at least he won't tell you to get lost if you try.