I know it has been 9 years ever since this game came out, but I need to make a few pointers on the myrm build for the female MU.
I've tried various kinds of builds and found that only orphan (+2 str) with kindness (+1 def; 5% growth doesn't matter) and truth-seeking (+30% hp) helped me get through the prologue. The other builds was not able to get past Jaegan...
However, it is important that you get good level-ups (str/speed) during the prologue because you are designated thief-killer in assassination. Your other units (assuming you get Ogma, Athena, and Cain) are mainly used for tanking.
Maybe I suck at this game, but this is based on my playthrough.
