Would creating a filter to group/list all the cards that are the test cases (I am assuming a Jira card for each case) then having got the filter correct there is a bulk edit feature (if your account has the permissions) and that might have the ability to link them?
Or if you don't need a link (like "relates to" or "causes") then how about using labels, again labels can be applied through bulk edit (and there can be multiple labels like "TestCases" to group them all and then "TestCasesPersonaA" or such like to also group by something else)
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