I've been throwing this idea around for a while, and I think I've achieved a good balance of making it worthwhile without making it overly powerful.
David's Sling
Type: Artifact • Brigade: None • Ability: None • Class: None • Special Ability: When your warrior class hero starts a battle, you may draw a card or play an enhancement. If an opponent's evil character taunts you, a hero may enter the battle to discard any evil character in play or set-aside. • Identifiers: OT, Depicts a Weapon • Verse: 1 Samuel 17:50