Kickout flashing around chimney? Help

Hey guys needing some advice. I have a leak in the basement foundation beams running in line with a mold/ dark area that runs up to the corner you see on the outside. I had roofers come out and replace the flashing but it didn’t fix it. I was going to add kick out flashing at the end but the step flashing that runs along the side of the chimney (can’t see because covered by cap flashing)is covered by the piece of cap flashing that overlaps it and wraps around the corner. So I’d have to cut a slit at the corner of the cap flashing to slide up the kickout into and use neoprene to seal it. So my questions are

  1. Is this the best way to do this? If not what is?
  2. Should I also get a gutter to connect to the gutter la you see on the left?

Thanks appreciate your help

It’s such a tiny area, start fresh. Cut counter up with a grinder if necessary, install kick out flashing at bottom and install a bell shaped collection box as a gutter.