Tri Force + BotRK is a shit tier build on Kog, stop rushing those items on him.
Kog is a fucking hypercarry, stop playing him like he's some kind of midgame ADC like Corki. Phantom Dancer + IE is definitely the way to go; it gives a WAY harder 2 item spike than Tri Force + BotRK, the only thing Tri + BotRK give are a decent up front burst. Kog doesn't even need a BotRK, he already does % Max Health damage on hit with his W, why would he need any more tank shredding ability that early into the game (2'nd item)? If you really want the movespeed from TF, just get Furor boot enchants.
Better go tell all the lcs players.