The whole point of this build is not too teamfight, but to split push your lane. All you have to do is feed your adc (I prefer nachos as it works well) and send them mid to teamfight. Because your carry is fed there is no real point for you to teamfight, and in most cases the jungler supports the team in teamfights. What do you do? Wait until you have your Thornmail and Iceborn Gauntlet and push. No-one can take you in a 1v1 but be wary when 2 enemies are missing from the fight. Use your Shatter to farm and your Radience and any ability you want too use too get the sheen proc as often as possible to push. With just the first 2 items you can easily take out the enemy adc in a 1v1, and maybe even the support in a 2v1 if you can outplay them.
Do this all game to prevent you enemies from ever being safe. Give them an ultimatum: Either they send 3 people down bot to stoop you or they lose and inhibitor. If they do end us sending 3 or more down to you it then allows your team to push mid or take baron. Don't worry though, using only your Imbue and Dazzle you can fend off enemies for as long as possible. Either way they are losing an inhibitor, which can easily swing the game in your favor if it wasn't already.