Talon need some minor changes
First of all, his Passive: His passive is basically the mastery : Oppressor. But its just higher amplification dmg and only on his auto attacks (He dosnt rely on auto attacks on his damage)
After last whisper changes, ADC becomes impossible to kill if they get any armor based tank item. Talon can only obtain maximum of around 40 armor pen from items. The current LW is not well-suited for him at all since his job is to kill adc, and the passive on LW is not at all, or barely useful.
I'd say give his passive a tiny amount of armor pen. Just an example passive could look like :
Passive - Mercy : Talon gains 3 flat armor penetration (+1 per level) against targets that are under any influence of crowd control.