[Doo]

Frost Brand and Fire Brand at Construction 4 are good as they effectively attack a whole "square" of units and not just one unit in the square. They clear mobs of weak units quickly.

There are some anti undead or anti demon options, good if you know you will be facing them, especially vs SC undeads.

Generally if you have a commander who has some innate survivability give them one of the brands and a shield (vine shield is a good one). Stick these guys (or gals) in with the regular troops and they increase the rate of killing. If your concerned about survivability then forge survivability gear, Pendants of Luck or armor. The idea however is to churn out as many of these guys a possible so the cheaper (in gem costs) the better. These guys wont take down an army but protected from too many attacks by being amongst your troops they do a good job of trying. Examples are the Niefelhiem giants (big, beefy and can be blessed), those Tir na Og guys (glamor and awe) or Banes (undead so no encumbrance and come with good armor).

I have not checked if the latest CBM has made whips better.... If not just stay away from them.

Dual wielding and 2-handed weapons are fun but having a shield is often much better.