1)vanguard is a noobish item, you can buy 2bracers for the same hp and half the price.
2)this one is a counter for mostly used chars (like mirana) and ruins their early game, and no farm early=no kills later.
3)DON'T take this if you don't have a good tank and can stay out of harm's way.
4)2 orchids is just stupid.
5)critical doesn't count damage from your orb, so NO.
6)he needs no buffs, since his orb is a great damage skill+orbwalking is just too good.
7)you don't need hood, since you should silence your opponents before they start casting.
8)you can triple lane with him and completely ruins someone's mana early to late game.
9)skill build: orb, aura, curse, curse, curse, orb, curse, orb, orb, ult, ult, aura, aura, aura, stats, ult, stats till 25
enough for ya?