Fix Duskblade now!
This is ridiculous. Riot tweaked this item to better synergize with assassins, and it does a very good job in my opinion. The true damage on hit makes the item function much more consistently than how it used to (with the % missing hp burst). However, it is STILL being abused by marksmen. The whole point of these itemization changes was to stop ADCs from using assassin items for the unintended synergies (ie attack speed buff on youmuu's giving a huge %AD buff to jhin). And while these itemization changes did stop marksmen from building youmuu's, I still see jhin building duskblade, and now I'm seeing vayne build it, too. This is so unhealthy for the game, especially on vayne, as her shiv/rapidfire cannon + tumble + ult bonus dmg + duskblade proc + ie crit is basically a one shot on squishy targets, and because she can no longer be revealed during stealth, it's also pretty low risk.
Here is my incredibly simple suggestion: duskblade passive only works for melee attackers. Done. So simple. This makes it a great pick up on assassins, but useless on the ranged champs that are currently abusing the fuck out of it.

simply completely outshines
, there is basically no reason to build youmu before or w/o it cause