What makes Brutus a powerful person how does this relate to how he is a tragic hero?

"Brutus has the perfect resume for a tragic hero. He's a decent guy but really does not understand his flaws and limitations. He ends up destroying himself and those around him. Brutus loves Caesar, but he loves Rome more. So, he ends up in a nasty conspiracy. Brutus's flaw isn't that he is an honorable guy, but rather that he thinks others are honorable as well. He cannot see the daggers beneath men's smiles and is easily manipulated by Cassius, “Three parts of him Is ours already, and the man entire upon the next encounter yields him ours." Soon after the funeral Antony turns the crowed against the conspirators and Brutus is pretty much done."