DotA 6.49 Secret Boss - How to defeat Kael the Invoker

To defeat Kael the Invoker you will think of 5 heroes ganging him? And what are the best group of heroes? I would say there is actually a hero could solo him - Ursa Warrior.

Secret Boss - Kael the Invoker (v 6.49)

The secret of it, is the third skill (fury swipes) of Ursa Warrior. It stacks 24 damages per attack on Kael the Invoker, the more attacks he made, the more damages he dealed.

Besides, you need some godly items (Heart of Tarasque x2, Butterfly, Power Treads, Divine Rapier x2) and a crow that carries Valdmir's Offering.

Item used:

With a crow that carries Vladmir's Offering flies around Ursa Warrior, Ursa Warrior could have 16% Lifesteal Aura. Starting he could not make much damage (as the Fury Swipes does not stack much yet), so we could see he is losing in HP. After some hits, we could see his damage is increasing and more than Kael the Invoker's HP regenerates rate. And also getting his HP back with the 16% Lifesteal Aura.

Do you have any other good hero or idea to defeat this secret boss - Kael the Invoker?