Problem:
The issue here is that the user wanted to add the pipe icon i.e "|" in between their unformatted list of post titles on their block view.
Solution:
Unfortunately there is no way to add this styling when you're using a the Block builder for Views. The only way you can achieve this is with the classic view setup.
If the classic view hasn't been enabled you can enable it by going to Toolset -> Settings and scrolling to Editing Experience. From there I recommend that you select " Show both the legacy and Blocks interface and let me choose which to use for each item I build".
This will allow you to have access to the classic editor as well as the block editor. From there refresh the page and go to Toolset -> Views.
When you create your classic view and select your post type to display and add your relationship filter under the query filter section, you will scroll down to the Loop Output section.
Since you're only displaying the Title of the author then you can just replace everything at with the ones below.
<wpv-loop>
[wpv-item index=other]
[wpv-post-title]|
[wpv-item index=last]
[wpv-post-title]
</wpv-loop>
From there you can just go and re-add your view to the page using the view block. Please let me know if this is clear or if further clarification is needed.