I have a lot of… opinions about Final Fantasy these days and how Square Enix is handling the legacy of the games that I personally still enjoyed.
So as much as I used to love Final Fantasy, I fear it wouldn’t turn out well.
Star Wars on the other hand? Star Wars gets a ton of spin-off things, has a huge backlog of semi-canon characters, planets, weapons and creatures (and a more than modest list of fully canon ones).
It even has precedent for a single character / entity needing to be protected during combat, in the Battle Meditation of some jedi (most famously in Knights of the Old Republic 1) where they can influence the morale and ability of surrounding friends and foes to tip a battle in their favour.
As long as it’s well realised though, I’d honestly buy a licensed Defender’s Quest for any property up to and including Teletubbies.