I like this version of Runic, Supersun. It's useful, simple, and gives me a nostalgic ability without being poo-pooed as too overpowered to implement. Also, in a sense, you could look at it as bouncing the mob's nuke back at them. If you make the MP absorption rate high enough, you'd have enough additional mana from a Runic use to nuke back in the traditional sense.

It does lack the melee encouragement, teamwork aspect, and the concept of taking hate for other mages, though. And there's something FFVI-esque I'd miss if I wasn't required to be wielding a sword to activate Runic! I'd ideally like to see SE work with the other Runic suggestions here in whatever balanced manner they need to.

In any case, I'd still make it a JA instead of a JT, so you have to time it. The other problem I have is that in this version it does sound more like a PLD ability. However, they do have a "Converts damage to MP" on their AF3 head already. Let's hope SE takes one thing RDMs are asking for and doesn't redirect it to another job.