Hi there Klestr,
In order to block emails from this specific sender, you would need to add each of these email iterations onto your block list. You would first need to create a contact to assign these emails to and then follow these steps from Block phone numbers, contacts, and emails on your iPhone, iPad, or iPod touch:
From the Mail app, open the email that has the contact that you want to block, then tap the contact at the top. Tap Block this Contact.
You can also move these emails to the Trash or mark them as junk using the applicable sections of this article: Organize email in mailboxes on iPad
If you would like another way to block these emails on your iPad, then we would encourage you to submit your feedback about this here: Feedback - iPad - Apple
Take care!