Sound logic and reasoning can be supported by evidence. What evidence do you have to support your position?
Your position that you are using an ad hominem attack? Your words come to mind. But you can look up the fallacy if you would like, or if you don't understand.
You have said all arguments for God do not use logic and reasoning but use imagination.
You have made a conclusion with no premises. You are attacking the subject of all arguments, not the argument.
But let us assume that you simply said, no argument for God's existence is logically sound.
Then at worse you are making a "all swans are white" statement using inductive logic which is impossible to prove. (Sidenote: you really should see Kant on inductive reasoning). But, nonetheless, induction is logic of a sort and certainly reasonable. However, all one needs is one counter example to disprove a statement like this. For that, I will use anslem's ontological argument for God.
However, in a transparent appeal to authority, I would also throw out Plato's first cause argument.
There are your black swan my friend, but you really should revisit your wording and move towards actual argument instead of attack.