Remove Death's Dance
It ruins assassins. Especially assassins that already take time to unleash their kit(Talon, Shaco, Kha'zix, Elise etc.). They're basically not even assassins against AD's. They burst most of their health and then they just heal everything else with their 12% lifesteal on AA's and abilities(granted only 33% for AOE) from the item, not to mention the other lifesteal from runes, masteries, and items.
When you build squishy, you need to be squishy. Granted this item makes you squishy and just adds the other damage for later, but it also gives you lifesteal so you don't have to give a shit about that damage later. Assassins were made to kill squishies, but now they can't and its complete and utter bullshit. Remove it.