Ancient Clan Strike is a 13th level encounter available to Barbarians. [PrP:17]
Ancient Clan Strike
Barbarian Attack 13
Your tattoos, scars, and markings burn with primal energy, guiding and empowering a deadly blow.
Melee weapon
Special: Before the attack you can take 3d6 damage. If you do so, then you gains a +1 bonus to the attack and do not expend this power if you miss
Target: one creature
Attack: Strength vs AC
Hit: 4[W] + Strength modifier damage
Rageblood Vigor: If you take the damage you also gain a bonus to the damage roll equal to your Constitution modifier.