After talking with a friend, I decided to spend more orbs on the 1,000 heroes special banner. My friend told me that everyone on that banner was pretty good, and some were really good for Aether Raids and Summoner Duels.
I was mainly pulling red and gray orbs since I still wanted D! Edelgard, but now I wanted D! Nina.
Results
I got decently lucky with my summons. I got D! Nina and F! Morgan from the first 24 orbs. Then I spent another 23 orbs and didn’t get anybody.
Combining my previous session with this one, every 6.66 summons or 21 orbs, I got a 5-star.
I am pretty happy with these results, but I probably should’ve stopped summoning after D! Nina. I thought I would get lucky again, but that didn’t happen. My goal is to keep 100 orbs at the end of this month.