>>50185454
We know from Rinnosuke that proper half-youkai tend to get the best of both worlds, which is mostly in line with the mythical basis, anyway. You'd probably be looking at a kid that could be expected to be slightly weaker than a pure oni without many of the weaknesses. That, and given how much it takes for oni to get drunk in the first place, combined with the ambiguity of how much "biology" nonhumans even have in Touhou, it's probably not likely to cause any defects.