The reason Ursa gets Vlads is its the only form of any orb/Attack modifyer he can get as Vlad's is an Aura, and allows him to make Rosh his *****. Of course if you have a Skeleton King its pretty pointless to get Vlads then, since the main reason for getting it is lost, and the damage isn't significant to get it.
His fury swipes is his built in attack modifyer/Orb, and also his main form of damage(most the game) and why he explodes heroes.
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Oh SuperNiceDog's doing it again dude.
SuperNiceDog, you ain't no pimp dude