If I am understanding correctly, are you saying that you want to update fields in a SharePoint list. Diferent fields get updated depending on the "phrase" in the message title?
"Email 1 Subject/Title" - Update Field 1
"Email 2 Subject/Title" - Update Field 2
"Email 3 Subject/Title" - Update Field 3
... and so on ...
If so, a good starting point for you may be to look at this blog - https://www.alanps1.io/power-platform/flow-try-catch-on-user-list-till-you-get-a-match/
Using the Try, Catch, Finally approach with the "Scope" connector will mean each Try (Scope) can check with a condition, if that fails, it will move on and check the next one and so on.
Here is what you would start out with: (You may want "Get Item" or "Get Items" to suit)
Here would be your first Try
Each Try that comes after would target a diferent subject/title until you've covered them all.
Worth a go?
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