Tranquils on viper?

Just Putting it out there : i have 12/14 wins with PA and medallion strat. It works, you start with 3-1-1-1 or 2-2-1-1 if you dont have last hits troubles. Get phase and medallion in 10-13 minutes at the latest, then start your carrier as a first rate ganker.
You can buy a bkb mid game or linkenspehere if they have a bkb piercing spell. Follow up with Skull Basher and Manta Style if you need chaos element and a nifty dispel .

Situationals include but not limited to ring of basilus , Eye of Skadi , Maelstrom / Mjollnir ,HoTD, linkenspehere

Your core 90% of the time is medallion phase and bkb.
You will never need smoke of deciet for rosh as you can rely on blur. That thing is so good at scouting roshan enemy attempts and also to go in without being seen.
Medallion also increases roshan potential as sanvitch so aptly concluded.