This is an insane crit damage build that I've played recently and wow does it rape face. The skill order could vary, but the reason I do it is because I try to keep as many stacks of bloodlust up at all times, as a backup heal. a max bloodlust rank at level 9 means that you heal for a lot more, and gives you more lane presence/farming potential. End game you can solo dragon in about 6-7 seconds depending on how many stacks of occult you have.
As a recommendation, gold permitting, try to keep elixir of agility up as much as possible, and get an avarice blade or two early on if the enemy is very aggressive. I usually get 1 anyway, and then sell it for the last whisperer at the end.
The last item can be situational...I've found a frozen mallet is very nice for a little more hp and the perma slow, its a nice followup to mocking shout. A lot of times in higher elo games, your jungle gets stolen anyway. If you want to solo baron/do more to a high hp opponent, get a bloodrazor for the last slot instead.