They Laughed At My First Item ...
... And you probably would too. Hell, I probably would laugh myself, but when you hear my logic it may make a little more sense.
First off, this was a bot game because I didn't know how it was going to go. I try not to take theory crafting builds into PVP games (to be fair, I don't really play PVP all that often anyways). However, I actually think this could be kind of valid in a real game.
During champion select, I called the support role and took Jhin. This is already pretty strange to a lot of people I'm sure. My thought was that this would automatically let people know that I wasn't really looking to go ADC.
So I think I've stalled enough on the back story. The first item that I built was Liandry's Torment.
See, some of you probably are laughing. "Why would you build Liandry's Torment on Jhin"
I'll tell you.
Jhin's W, Deadly Flourish, applies spell effects as a single target ability. Liandry's Torment burns enemies for 2% of their current health per half second, for three seconds. This damage is doubled when the target's movement is impaired.
Now, this really isn't all that impressive. However, the massive range on his W means you can easily be a very annoying poke support. Pair this with the Deathfire Touch Mastery and Rylai's Crystal Scepter, your poke will be strong enough for you to begin burning down enemies health before they even get close to you.
This probably isn't even really best as a support role. It actually might be best on AP Mid Jhin, but I was actually kinda hoping to get my ADC fed like a good support, which did happen, but instead of just steamrolling bot, they started roaming. Which was fine because I was strong enough to split push.
Idk, may be stupid and completely worthless to everyone else. It definitely isn't stronger than other items, but I thought it was an interesting item + ability interaction, and the fact that the people in my game pointed it out and laughed just made me think that maybe nobody has even really considered it.
, which will give you more poke damage on W due to arpen and the ad ratio, as well as giving alot more damage to everything else you do.

while a crit build is better late game if the game gets that far)
The only ones that are situational or depend on the enemy are
and 
