Tropes applying to Shiffna Ronpa 1:

Adaptational Angst Upgrade: Applies to most of the characters, but Daroach definently gets it the worst of everyone- being a former blackened and dying horribly does that.
Exact Words: What the fourth motive is based on. It says that there's one former blackened among the group - which of course attacks 3 people in particular. Six is a primary suspect due to him killing the previous chapter, and Kaede believes its referring to her in V3, but in actuality, Daroach is the one being referred to, shocking everyone in the trial when he is forced to confess to show that he wouldn't kill for the motive.
Love Makes You Crazy: To say that Ally went crazy would be a disgusting understatement, though.

Tropes applying to Shiffna Ronpa 2:

Adaptational Villainy: Given that Sig is the host of the second Killing Game, he is placed in this trope for obvious reasons.
Even Evil Has Standards: If Austin Sanders has a problem with the Killing Game, you probably didn't make the best decision hosting it. It gets so bad that he actually attacks Sig, the host of the game who is a kid when hurting children isn't something he'd ever do in canon.