I talked it over with my co-mod and while we'd like to keep the game centered around fairy tales, we're going to do sort of a test run and allow them for now, provided the myths you're pulling them from are widely regarded as fictional and not actively practiced religions.

As examples: Greek, Roman, and Egyptian mythology are okay. Christian and Islamic figures are not.

We're also going to hold off on the major gods for now, and prefer characters based around specific stories, like the two examples you gave.