People do tend to forget that Plas spent three thousand years drifting around the bottom of the ocean. Considering that, he's actually a great deal more sane than one would expect.
I'd love it if this became the regular League lineup, with maybe a few additions (I'd be curious to see Dick-as-Bats join, but I'm sure they won't mix that mess into this one). They need someone tech-savvy (Blue Beetle?), and a super-norm like Red Arrow or Hawkwoman. A magician (great opportunity to bring back Dawn as Manitou Raven...) A speedster might be nice. And Wonder Woman or one of the Marvels to round out the power set. Yup, that would be a good JLA. Shame it will probably never happen...