Approaching lategame your item choices can vary a lot based on enemy lineup either max rabbit or ult next and itemize around that.
This is primarily a PUSHING build Sinclair is the best walker killer in the game this patch and stacking movespeed / sustain like we do lets you put crazy map pressure out the entire game while being very hard to catch.
Endgame Choices
First 3 items is my preferred order if maxing rabbit first if you max ult first go off vibes.
9/9 update: Big overall build change to suit how I've been playing and winning a lot since the patch. Abuse this heroes objective damage while you can :)
Feel free to ask me any questions on the Sinclair discord @RAIGEKI