Black cleaver on Talon

Definitely not bad, it gives some chase potential, a little health to survive sticky situations, and the CDR is really nice. With the removal of the flat pen, however, it doesn't serve your burst rotation as well as it previously did. It's much more important to get last whisper earlier, but I don't think that means that BC is a useless item on him. Your full combo, when used on the enemy team, will still do an excellent job of removing armor from their team, making any physical damage followup from your team pretty effective.

It makes him able to stick to his target since the movement speed boost applies on the Q DoT. The stats on the item also synergize well with him. Finally, the armor shred synergizes well with his many % damage boosts, further amplifying the damage he deals. By the way, Talon is one of the few champions who can fully benefit from building the 3 armor penetration items since they can now all be built together without any wasted stats. Put an Infinity Edge and a Trinity Force along with some boots in there, and Talon is dealing a LOT of damage.

I've noticed I do like zero damage when i build it

if I have an AD toplane as well as my adc, I might build it after the other armor pen items tho

Lw

I always built Black Cleaver on Talon, and I still do. I like the new one better since it builds out of Phage and gives more CDR/Health than it used to. I haven't even noticed the loss of flat penetration. That extra CDR from it allows me to stop building Boots of Lucidity to reach the CDR cap (without Blue), so I can situationally build Ninja Tabi/Merc Treads or Mobi's when ahead. I find it's an overall better item on him than before.