Rengar- How to Build the New One Currently

There's nothing wrong with building Bruiser on an Assassin. Riot doesn't mind things like Tank Ekko or Bruiser Rengar being viable so long as they make fair trade offs for opting towards those builds.

Is Rengar's .5 second burst cut with this build? If so, it's fine. If he kills you within 3 or 4 seconds, it's still fine; it's no different from when or any other Bruisers do it.

His W isn't the main reason. His W only exacerbates the problems the passive's SCALING (not the passive as a whole) causes. +30% bonus AD as a bonus means he can build less AD. Which means he can build tankier. Which means he heals more Health with his W. If his passive's scaling wasn't so absurd, he would still need to build full glass cannon. Which makes the W heal less, as he's a glass cannon, meaning, the timing on the W for the heal needs to be pinpoint precise if he wants to actually survive against a coordinated team.

It's not like Bruiser Rengar is anything new. He's always had a high CDR fighter build that gave him good sustain through his W uses, when that CDR ensured that he was stacking his Ferocity really quickly. That synergized well with SV.

Basically My Build was Warrior, Lucidity boots, SV, And then maybe hydra for even more sustain a clear speed. And that was before the rework. Riot probably leaned on that play style a little in order to increase his burst window.