If this was the souls not the soul modes, it means:

ASGORE is BRAVERY (i'd fit him in something like idk 0.5 justice?)

METTATON is JUSTICE (there is nothing that can fit him)

MUFFET is PERSEVERANCE (luk idk k?)

UNDYNE is KINDNESS(nope, put her in justice)

FRISK is DETERMINATION (reasonable)

PAPYRUS and SANS are INTEGRITY (maybe a bit sans but no)

TORIEL is PATIENCE (reasonable, might add a bit(a lot of) kindness)

FLOWEY is NOTHING (we COULD put him in perseverance)