Is this your thesis statement?
The play, The Merchant of Venice by William Shakespeare as well as the film, Oh Brother Where Art Thou? by Joel and Ethan Coen clearly displays how Antonio and Ulysses, the heroes, love for another person, gullibility and vanity eventually bring forth their downfalls.
Whether or not this is your thesis, it needs to be greatly shortened or divided into two sentences. There are reference and comma errors in here that make it very convoluted.
When the hero falls in love with another person, he loses all sense of logic and probability which in turn bring's forth the hero's downfall.
(Delete the apostrophe in "brings" -- it's not a contraction or a possessive, simply a 3rd person singular verb!!)
Perhaps all you need to do is make it a bit more general. Try something like this:
When someone falls in love with another person, he often loses all sense of logic and probability.