Extus, Oriq Overlord is one of the cards that jumps off the page to me when looking over all the cards in Strixhaven. I, of course, imagine a perfect scenario where I’m playing my four mana card, it’s staying a live and then my opponent is tapping out for a 12 mana creature that has no effect when it enters the battlefield. Then I’m untapping and using the Awaken the Blood Avatar, sacrificing a Bonecrusher Giant, triggering Extus, returning Bonecrusher to hand and removing the opponent’s creature for six mana. Day dreaming is fun. In reality, I think this scenario isn’t that far-fetched. Extus seems super powerful to me in a deck with adventure creatures, and Awaken the Blood Avatar also seems very strong.
Note that Extus can only return nonlegendary creatures, which unfortunately prevents you from looping multiple copies with itself and returning Awaken the Blood Avatar every time, so you’ll have to do it differently.