Who is Matthew Hull from Broken and what is their importance?

Matthew Hull is an accountant from Victorian Englnd. He convinces the pack that he was thrown into the portal by his biggest and only client to act as a servant to Jack to Ripper. The pack doesn't know if they should believe Hull's story or not.

It turns out that Hull is the controller of the portal. He created it to hide his immortality experiment as people were coming to try to steal it from her. Hull walks out of the portal right after the first zombie to try to find the missing ingredient he needs to complete his spell. In the interim, Hull kills Anita Barrington and tries to take the twins Elena is carrying hostage, so he can sell the babies on the black market.

Hull winds up dead. Elena rips his throat out. Once Hull and his zombies are dead, the portal does close