Thx for the fast translation.

Possible guesses:
1) Mystia was saddened by the sheer cannibalism Mokou had committed.
2) Mokou decided to eat other eggs than hers.

Somehow, I am going for (2).

Dem babykillers.

I eat babies for breakfast.

I'm going with choice 1 F.I.A provided, Mokou was making eating chicken.