Brand

Thanks to explosive arrows, Brand is a viable choice for fire auradins and enchantresses. However, it lacks pierce, so Kuko Shakaku or Demon Machine may be a better choice.
Also, if our build is purely elemental, and we use Lower Resist on a switch, Brand's Amplify Damage proc will override it.

Main disadvantage of this costly and otherwise powerful runeword is the lack of inherent speed. Compared to massive stopping power of an Ice, or speed of Faith, Brand remains unpopular choice.

This runeword seems designed for necromancers/non-amazons:

synergizable proc? Check (for necros only)
Ignore target defence? Check - no ar issues on normal monsters
Bonus to attack rating? Check - helps against bosses
Turns regular

Arrows into fire

Arrows? Check - extra damage at no mana/skill point investment
Chance to do double damage? Check
Bonus damage to boss? Check - and all demons
Knockback? Check - adds lots of safety
Prevent monster heal? Check - ‘cause it sux without
Procable amp damage? Check - if you get hit it can be beneficial

All you need is some increased attack speed and leach and anyone can make this as a viable main weapon.

It works best on a necro, but can be useful on a shape shifting druid, and with the 2.6 patch an enchantress really can put this to use too.