In the yard of Castle Karstaag Ruins now you can found The Zahkrii Do Dovahkiin. The sword, the true power, which is revealed after shout *Become Ethereal*-FeiM Zii (Zii* is necessary!!!). Increases the speed, critical damage of sword sold short dominance over the enemy and raises chance of Fatality. 

That is really losted sword. Oriqinal files of Dragonborn we can find the different part of this sword (shout, effect and etc). Im only connect them and reconstruction The Zahkrii Do Dovahkiin. Thuum activate the *Rage of the ancient* effect and Player get global value in the fight.