Ok I will be honest. I want to go with a build @lordgorgon had recommended me. It is called the RICO build, which is with
Mercy + 2 Nightfalls + all utilities (Maybe I could add a nighteagle.)
So, just wanted to know how rare Mercy is. I know that it is rare as sh*t. But, just wanted to know how rare it is and the chances of getting it.