I imagine that as a result, this might not actually be a troll build. I'm not sure. It might be a legit seriously viable build, albeit probably only in select circumstances.
Basically, I believe the best runes for this (really not sure), are Press the Attack, with Triumph, then Bloodline (the only Legend rune which is useful when you're going to hit the attack speed cap with no method of exceeding it), and most importantly of all, Coup de Grace (for the obvious reason).
Secondary tree, best I could come up with is Cheap Shot and Eyeball Collection. I'll be honest, the runes for this wouldn't be the focus, the focus is more in the items.
I do think that this probably benefits from the double-adaptive extra runes (and then maybe health?), and then the items are...the five items which give unique health/armor shredding, plus Boots of Mobility because that's the boots which assassins take and this is a build inspired by them to some extent.
Rageblade is probably the first item, with Mobi Boots as second, as per usual. From there, not sure, but the other items are Sanguine Blade (for the unique lethality, and in an isolated matchup, one of the highest lethalities of any lethality item), The Black Cleaver (up to 24% armor reduction), Mortal Reminder (flat armor pen, plus grievous wounds--grievous wounds > extra 10 armor pen), and Blade of the Ruined King (for the passive 8% health shredding).
Tanks on the enemy team...would not have a fun time.
But I imagine it's not a very balanced build overall.
Might be good in select circumstances, and I added it to the list of my for fun builds, even if it might still be a troll build.
Worth trying out tho!