Having trouble creating formula to show 1 of three outputs based on matching information in columns

Hello everyone. I am trying to compare assets in 2 databases.  There are varying numbers of assets in each and I want to create a formula that compares which assets are replicated in both and which are unique to one database and not the other. I have a workbook with two sheets, one titled Webfinity and one titled CSOD. I want to compare the value in cell ('webfinity' z:1) with any value in ('csod' I1:I500). If it finds a match, I want to populate ('webfinity' z:1) with "both", if no match then "webfinity only" and (the really tough one) if a cell in ('csod' I1) does not have a matching value in ('webfinity' z1:z500) then put value of ('csod' a2-z2) in the next available empty row of 'webfinity' and putting "csod Only" in first column and the remainder of data in adjacent columns.

I can get the first two to work by applying a formula to all and then, sort and apply a different formula to those that remained blank. Formula: =IF(IFNA(MATCH(Z65,'Partner CSOD'!$I$1:$I$500,0),0)>0," Both","") I changed to =0 to return "webfinity only". 

If no way to create one formula for all of it and paste down the sheet, would at least like a way to do the first two together in one formula.

Thanks in advance for your help. Happy to attach spreadsheet, but not sure how 🙂 First time posting.