For those of you looking to do the Agonarch Rune I've figured out how to get it done. There's been a bug where only Dakkadi has been appearing, which means you can technically only get one charge out of seven for it. You usually need to kill the seven different Taken bosses who appear each day of the week to fully charge it, but like I said, only Dakkadi appears. I've discovered that if you kill Dakkadi once a week after reset you can fully charge the Agonarch Rune. It's time-consuming, but for those of you looking for that Calcified Fragment it's definitely worth it. Please spread this info along.