@Riot, DeathDance: who is it intended for?
[Please, do not comment with something such as "Nobody, it's a trash item." Thanks :) If it's just a power-level issue, it can be number-tuned, but my question is about the item's design.]
Who is DeathDance targeted for?
Quite obviously, with raw AD and CDR and pseudo-lifesteal on skill damages, it's for AD Caster. But what AD Casters? I mean, Assassins like Zed or Talon don't really want Lifesteal, neither Fighters like Garen or Renekton or Vi.
And for ADC, the caster-like ADC usually go for Essence Reaver + Trinity Force, so the CDR on DeathDance would be over the cap already. Additionally, DeathDance applies only his pseudo-lifesteal, it does not synergize well with other lifesteal items (contrary to BtrK or Ravenous with their passive, for instance).
So I'm lost, I don't understand who is even supposed to be using this item...

for low hp sustain from the damage amp and %vamp on everything stacking his w's increased healing.
as his 2nd damage item since DOTs apply the full 12% vamp essentially making his bleed a warmogs late game
, so I might replace ghostblade with death's dance since it gives more AD, equal cdr, somewhat tankyness via passive, and that heal.
instead.
I don't build triforce for the phage. I build it for the ~270 damage on sheen proc, the 20% crit ( I run crit runes), the 5% movement speed, the 250 HP, and 10% cdr.
I especially get it if I need to assassinate a high priority target, which is how I like to play Garen.