Caldor is a realist, although he is secretly a optimist. He wants to best and hopes for the best outcome to a situation but he will not say it out loud. If asked, he will give you a realist answer.
Foe is an optimist. He tries to find hope in the most hopeless situations. If he was in a hole, in the dark, with no source of light… well he wouldn’t complain. He would find the silver lining even if it’s ‘at least I’m not dead’.
Liora is a realist. You can thank Caldor for that. She accepts what is happening and lets it roll of her back. Every situation has it’s reasons and every reason leads to another situation. She will tell you how it is.
Pellar is a pessimist. He always sees the sky falling and believes that the world is out to get him somehow.
Charn is… well I’m not sure yet… he’s still in development… though I can see him as an optimist with realist traits.