Trinity Force on Kha'Zix?
What do you guys think? I haven't had a chance to try it, but apparently it's pretty decent for the burst Sheen gives. I know there's "Diamond 1 Khazix," a Challenger Kha'Zix main, who buys it second item almost every game (right after Hydra, unless the enemy has tons of armor early or if way behind), after his jungle item.
(neither
nor
have stats that are really good for him) if you are building as a squishy assassin. And because all his main damage abilities are physical damage, you cannot afford to delay armor pen items by very much. Furthermore, base AD scales less with levels than base HP so it becomes far less impactful of a pick up the later you get it.