Soul Traits

[Aniikinis]

So I was bumming around on youtube and came across an Undertale fan-series by the name of Glitchtale. I started skimming the wikis for UT and anything I could find about the series and I got an idea for a few feats and/or maybe a class idea. The only problem is that I'm not sure what I should do with it. The idea was fairly simple and was touched upon slightly in the game itself but the fan-series expanded upon it. Each of the 78 human souls has a colour and a form of combat/mentality associated with it, the most commonly known is Determination and is associated with the colour Red.
So here's my dilemma, I'm not sure if I should make a modal/archetype-based class or a few [Soul] or [Heart] feats that must be taken upon character creation that add bonuses and roleplay opportunities for the character.

[Westhart]

Hmm, I have never played or watched undertale, but my little brother likes it...

I emailed him, seeing what he would like and of course being as unhelpful as possible he said both... but he finally admitted a class *might* be better...

Either way, I'll peach it if 3.5 and good luck!