Phantom second job skill

Get Mental Clarity, from Brawlers. Rage had some slight compatibility issues in the past, but it might have been resolved (I wouldn't know).

I thought people usually got Hyper Body for this... but now there's also Monkey Magic, or Bless (not terribly good or bad), or even (maybe) Soul Arrow! You could try your luck with Magic Booster but I doubt it'd work.

Hadriel

Rage was fixed ages ago, now has damage reduction (which admittedly does nothing on % HP attacks, but still), and is a party skill. As far as I know, all Phantoms use Rage, but you should also have Bless or Monkey Magic for the off chance that you happen to be in a party with a Hero-line class or another Phantom.