Since he knows that he is the Fourth Child, Toji is taking an entirely new dimension.
And then it happened. The thirteenth Angel was in fact the Eva Unit 03. This is just perfect writing. Shinji having to fight the Eva, knowing there may well be a child inside of it, but not knowing that the child is actually his friend Toji.
When Shinji refuses to kill a human being, his father Ikari commands the team to implement the dummy plug and take control on Shinji's Eva Unit 01.
This is a brilliant scene. One of the most memorable moments of the entire series. Unit 01 tranforms into a blood-thirsty ferocious animal.
One of the best episodes of the series. I give it 10 out of 10. My favourite episode of the series so far.