Finding a Single name in Cell in a Cell with Multiple Names (words)

Looking for a formula (not macro) that can do the following:

I have a spreadsheet and in one column, it has last names of clients. In the next column, it has full names of clients that are the same account, but different system with different descriptions for the name. I need to lookup the column that just has last name and see if that last name exist anywhere in the "Full name" column. If it does, then I need column C to say "Yes" or something along those lines.

The "full name" column isn't always in the same format and sometimes doesn't even contain the "last name." Sometimes the last name will be first and sometimes there's a comma and sometimes there isn't a comma. The spreadsheet attached shows a good short example of what I'm working with...

Thank you all for your help in advance!
Perm
Name Spreadsheet Ex.xlsx