Why these items?
The logic behind my item choices.
Early- 2-3 null talismans into power treads standard, but rushing a ghost scepter is a choice that turns heads. Ghost scepter for me is one of the best / under used items in the game, but on Outworld Destroyer, it's a great source of early stats at a relatively cost effective price. Plus it allows you to cast Arcane orb while you are ethereal (activation of ghost scepter) which silencer can do as well.
Mid game- Rod of Atos was made for this hero. The cheapest 25 int and 250 health item you're gonna find in DotA. On top of a cripple debuff (50% movement speed debuff). The perfect item for OD since he lacks a disable outside of his imprisonment.
Late game- Refresher is a phenomenal item considering the first two items Ghost scepter, and Rod of Atos. You'll get 8 seconds of physical immunity, 2 cripples, and two ultimates. And even if your ultimate doesn't reach the damage threshold, two ultimates will completely kill the enemies mana pools. A great counter to heroes like Leshrac and Storm spirit(more to name). Following refresher you work towards your sheepstick. Which I don't need to explain why it's good.
End game- OD has some of the highest end game damage outputs, so all you need with a decked out inventory is a **** ton of health to not die with. Heart makes this happen.