@Izaya_Onisai well.. he just look like human, then hes treated like one.... i think
and about mana...even when you combine two persons with huge mana capacity, you can get person without any... theres no rule he inherit that, but his child can.
sometimes child dont look like any of his parents, some genes are inherited even after some generations
example i, and my siblings, have genetical illness, but theres not record in my family for 6 generations of of it... so its inherited from someone even far in my bloodline.
(this illness is recognizable - skin color)