Something like human paladin (holy warrior variant) 4, feats H) two weapon fighting 1) law devotion 3) power attack 4) divine might could work in a low op game; add two levels of fighter for 5) weapon proficiency (bastard sword) 6) oversized two-weapon fighting 6) improved two-weapon fighting, and you have:
- 4 attacks at level 6, 2x 1d10 + str, 2x 1d10 + 1/2 str
- as a swift action you can increase to hit (law devotion) for 1 minute, if fighting a low ac creature fuel power attack with that to hit bonus
- free action: add cha to damage for 1 round
Should work in a low op campaign, if you have the stats (need decent strenght, dex, con and cha). Another option is to go for animal devotion, it also offers some utility (the ability to fly), and can give a flat bonus to strength (and thus damage) as well. Prolly want to include 'extra turning' somewhere, or get more turn attempts from items.
Probably after 6 levels of this, it would be best to take a few levels of martial adept and prestige out, or go for a partial casting prestige class.
Of course, cleric can do the same, and gives more powerful options, like the flat bonus from the holy warrior feat (not to be mistaken with the holy warrior ACF), as well as divine might