Bloodthirster is designed as an AD Caster item to grant massive damage.

At first glance, Sanguine fills the same role... But the reason Sanguine is bad? AD Casters aren't spending all their time auto attacking to build up charges.

Sanguine needs to either build charges with abilities use (as well as autos), or BT needs to make a return to TT.

agreed

I'd argue that any item with lifesteal is not an AD caster item, because they don't spend a whole lot of time auto-attacking to make great use of lifesteal, compared to an AD carry. It's a lot of money to spend when the goal is attack damage, not lifesteal.

That being said, there are two problems here. BT is an AD Carry item that fills a partial role for AD Casters: big-ticket AD item. Sanguine Blade servers as a replacement for the AD Carry item, but removes the effectiveness as a big damage item.

This is where the new Black Cleaver will come in. It's a big AD Caster item.

Right now, on TT, when I play a champion like Pantheon or Kha'Zix - BF Swords are often a last resort. I find my damage doesn't suffer when building Brutalizer, Hex Drinker/Maw, and Last Whisper. I often don't have the opportunity to build glass cannon, stacking BF swords, because I need to survive long enough to take down the bruisers.

Thats the whole point. They didn't want a lee sin to 3 hit the enemy vayne lol. This way bruisers cant get 100 AD for 3k gold, and just kill an enemy carry before they can respond.

Lee isn't even weaken :P actually a lot stronger just saying haha.