How do I modify the result?
You can use HOOK_views_post_execute() and cycle through the results rows,  updating the row with something like:

        foreach ($viewExecutable-&gt;result as $key =&gt; $rr) {
          $title = $rr-&gt;_entity-&gt;getTitle();
          // update $title value...
          $viewExecutable-&gt;result[$key]-&gt;_entity-&gt;set('title', [['value' =&gt; $title]]);
        }