Maddison Mikealson is the daughter of Elijah Mikealson. being an Original means Klaus can dagger you and put you in a box and every time Elijah did something to piss him off he took it out on Maddie daggering her and putting her in a box until Elijah did what he wanted sometimes it was decades before Maddie was awoken again. 50 years have gone by since Elijah seen his daughter all because Elijah was done running and wants to be reunited with his siblings and daughter and Klaus had other plans for his brother because he tried to kill him. Elijah is reunited with his siblings but after 50 or so years Maddie is woke up. Being a hybrid of her own and Klaus needing a powerful witch and wanting to punish her dad wakes her up soon after daggering Elijah.