User blog comment:Megames1/Ursa in The League/@comment-79.175.67.68-20121002234048/@comment-79.175.67.68-20121003123433

And that is where Nasus's ultimate goes in, it does a percentage of health as damage while converting that damage into additional damage for Nasus. Add thornmail as I stated above since Ursa relies on auto attacks an voila.

Also wither slows down attack speed. So if you cast wither on Ursa and he uses his attack speed sterioid he would have a buff of 6 attacks, but instead of having 2.5 attack speed he would have almost 0. He would strike once or maybe twice and after wither ends he is left with only 4 strikes.

But health alone would kill him since Nasus has a team wrecking ultimate.

Also how about Madred and Deathfire. Do you have similar items in dota. I don't play dota so I really don't know about it.