For me, I have two accounts at DMM for Aigis. My first account got the gold druid as my first pick while my second one had the silver burst archer. Idk if the whole deleting your account and recreate it works for DMM, so have another e-mail to register. You could consider rerolling, though with revivals at DMM, getting higher rarity units is far easier than Nutaku Aigis. And some events (like the previous princess event) drop platinum units such as Belinda and Hana. That and you can try to gather DCs whenever you can for the TP units which rotate every month. Look out for when the drop rates increase during events because those help a lot. I ran Crystal Keeper H several times during that time and got full drops most of the time.