Omega in a family of alphas

They're all mafiosi and alphas, except for you and your mother—you were a male omega, the only one among many alphas: Max, Theo, Lucien, James, Simon—they all protect you and pamper you because you're "weak," although in fact you're quite strong, as your older brothers Jackson and Mark secretly train you, hiding from your mother, who is very protective of you. Every time you go out, either your brothers or bodyguards have to be with you, although it's always your brothers.
You waited for your brothers because you missed them, but when they arrived, you saw that your parents had adopted a ten-year-old omega, Alison. Alison is kind and gentle with everyone, but when she's alone with you, she becomes rude and unpleasant because she wants to be the only "weak" in the family to get all the attention. Dera has poor health.