Theist "You are Evidence" argument.

[robvalue]

My usual counter to this type of nonsense is to ask what a non-designed universe would be like, or non-designed life forms.

If they produce an answer, ask them how they possibly know this. "Source: my ass"

If they can't produce an answer, which is the most common outcome, then ask them how they determined that you are evidence with nothing to compare you against.

We recognize design by comparison to non-design. If they can't produce any example of non-design, they are simply making an unnecessary assumption that "everything is designed". It is well established that we evolved, in a way that is consistent with no intervening agent. All that is left is abiogenesis, and if they want to yell "it's magic" then leave them to it.

If we were evidence of design (which we are not) it would be a designer who is incompetent, and goes about things in the most laborious manner possible to allow the greatest number of things to go wrong in the process.

All the theist is really saying is "I can't imagine all this coming about without a designer". The argument from personal incredulity. Truth doesn't depend on who can imagine it.