OF has a ton of feats to benefit a single spell, most notably Spell Perfection, which lets a single spell benefit from any one metamagic feat (other than heighten) at no cost AND has all mumerical bonuses for it from other feats doubled. Hello, Shadowcraft Mage!
Imperious Command feat combines well with the various feats PF has to intimidate on every single melee attack. Most notably Enforcer or Cornugon Smash. There's also a feat that requires +5d6 sneak attack called Dastardly Finish. Lets you coup de grace cowering foes... And 3E has a feat to CDG as a standard action...
It'd be pretty feat intensive, but could be cool to incorporate some or all of that.
Also going back to Imperious Command, PF has a feat to demoralize all foes within 30 ft as your action, Dazzling Display. It also has a BAB +11 feat, Dreadful Carnage, to get a free demoralize on all foes within 30 ft every time you down a foe.