User blog comment:FairyRaven/Fairy Tail Chapter 467: Mother's Key, Review and Commentary/@comment-7418318-20160107102332/@comment-7418318-20160107152710

I'll just ignore the word analysis and go back to the original topic if you don't mind :P

Regarding how Brandish might have ended up a Spriggan, I have several ideas how that might have happened:

She might have feared that Layla would have her killed, so she fled as far away as she could. Another continent is a pretty good choice if you want to get distance between yourself and someone you believe is after you.

With her ultimate goal being revenge, she dedicated her life to becoming strong, which sooner or later got her noticed by the people in charge who recruited her. With them having many strong people, Brandish saw this as an opportunity to become even stronger and/or gain allies. Remember that back then the Heartphilia Konzern was quite powerful and influential and even had connections to Fiore's royal family (Hisui herself told Lucy that), so powerfull allies seem like a good idea to have if you want to oppose such a power-base.

Then there's also the possibility that Zeref somehow learned of Brandish's obession with taking down Layla and/or her offspring. He thought that with their connections to the Dragons and their common pasts, Layla and her clan are a potential threat to his plans, so he took Brandish in and groomed her as a counter to this threat.

Then there's also the usual chance or destiny routes and such. As unexciting as they might sound, with the way Marin was dealt with off-screen those are still all too valid possibilities.

Now for Jacob: Why would he get involved in the matter between Layla, Grammy and Brandish? What reason could he possibly have had all those years in the past?

I can't believe them doing a commando-action in the middle if Ishgar just to get their hands on a potential recruit, when they have an entire continent from which they can recruit members.