I just like this question in particular, so A for any character you'd like to answer it for?

DnD alignment... it's hard because of how the kids try to be vs how they actually are.
Chara started out pretty Lawful, although they've been getting increasingly more Neutral, but they'd see themself as Chaotic.
Frisk tries to be your standard Lawful Good paladin type but psyche they are totally Chaotic Good.
I mean, good and evil are kind of tricky

in the context of Undertale especially

I would say Chara is Neutral, on the morality scale, while as mentioned Frisk tries to do Good (but isn't always successful at it)

outside of DnD I basically made their central tenets and conflict as Deontology vs Utilarianism so take that how you will.

(oh yeah, and Chara would def peg themself as Evil if asked, no question)