Bane of Argonnessen( Dragonmarked, p. 135)
[Fighter Bonus Feat, General]
Your Siberys dragonmark swirls as you battle dragons, empowering your weapons to deal greater harm.
Any Siberys dragonmark,
Any magic weapon you wield deals an extra 2d6 points of damage to dragons or any creature with the dragonblood subtype (see page 140).
A fighter can select Bane of Argonnessen as one of his fighter bonus feats (PH 38).