Hello, and welcome to my Tryndamere guide. This is a build that I found to be really really good.
Why it works: Hail of blades gives you very good quick trades, and lets you proc your Blade of the Ruined King super fast, and lets you stack you Phantom Dancer quickly so that extended trades are still very good. This build is extremely good at low elo, because of the massive amount of tanks/bruisers in the commonly played field.

With these runes, you have a massive amount of pressure at lvl 1-2. Hail of blades lets you get insane trades, and if you get some lucky crits, you can straight up get first blood and win lane. Middle game, you have a massive power spike when you finish your BORK, and another huge one when you finally get your mythic first item. When late game comes along, the other massive advantage of this build comes along: Teamfighting. Usually, tryndamere will split push and try to take inhibs and get gold for his team. But in low elo, where you may very well be the only one on your team with more than 7 gold, teamfighting is a necessity. And this build holds up, letting you E in, 3 auto a carry and one shot them, and use BORK movespeed to disengage. Because of the attack speed, it also lets you get your E up very quickly to spin further in for chase, or to spin out. That said, this build doesn't lack split push power. The speed from your BORK and PD will let you dive easily for split pushing, and a fully stacked PD will let you take towers in a snap. Anyway, Thank you for reading my guide, and have a nice day!

P.S: If you are high elo, I have no idea if this build will be even viable at that level.