Riding Death Prophet to Win City

I wouldn't recommend Orchid Malevolence on Death Prophet. It's not horrible, but it provides zero survivability and is outclassed by (and generally unneeded alongside of) Scythe of Vyse. Shiva's Guard, Assault Cuirass and Ghost Scepter should all be noted for the resistance they grant to physical damage. Eye of Skadi is another option, providing +675 HP, +3 Armor and a valuable slow that penetrates Black King Bar. Consider Arcane Boots as well; you can make them early, dissemble them into Bloodstone later and then build Phase Boots or Boots of Travel.

Skill build is spot on, although Silence can optionally be taken pre Level 8.

Lastly, you can use BBCode for skills, rather than coloring them. See here: http://www.mobafire.com/league-of-legends/forum/dotafire-support/bbcode-guide-783