grrr... this is why I fell from s1 to s3 this last 2 weeks

how do you get to silver 3 and not know that mundo should be building tanky, especially when you are behind. He went 0-14. I'm fairly certain he was trolling. I called top voli, and he locks mundo. He says he's never played mundo before (once we got in the game), and when I gave him the advice, build full tank, a lot of Health. instead he builds a triforce, and then starts a triforce (he didn't finisht he triforce before the game ended). like wtf is that...