Most of the Heralds did not want to hurt Ipniani as she fought her internal battle, but the dragonborn handily rebuffed the party's attempts to restrain her. As Tobias got tangled his own net, Izek decided to take action, and popped her quasit like a mosquito. He ran his sword through the paladin, but found that Ipniani was protected by some arcane abjuration. She fought back with fire breath, smites from her Masterwork morningstar, and Fekre's festering magic, but the party eventually whittled Ipniani down. After enough damage, her protection shattered; she had been hiding the control amulet to the Shield Guardian, though had not realized exactly what it did.
Facing certain defeat, Ipniani gave herself to Fekre, just as Mormeros had, and was killed instantly. Sickness covered her draconic form as a wave of disease pulsed through Izek and Ajuni, causing the two to bleed and rot. The Heralds had to strike her down before the Dark Power fully took her body, but having slogged through the temple, they were drained of might and magic. As her friends were enveloped in poisonous darkness, Ajuni grabbed a spell scroll and leapt forward into the maelstrom, and dispelled Fekre's possession. In a snap, the influence of the Dark Power was broken, leaving only the paladin's rotted corpse.
Ghalwin saw Ipniani's situation as a mirror of his own, and cured his friend's sickness as they took a moment to rest and reflect. They permitted Khazan to restore the rest of the temple without them, and went to Neferon to collect their prize. The arcanaloth sent them a chest trapped with poison needles, but Tobias was wary, and used his new wand of secrets to discover the fiend's "prank." Neferon relented, activated the trap, and let the Heralds sort through the useless trinkets and baubles within. Ghalwin was disappointed to find that the Bright Blade had been shattered, but the weapon seemed to sense inherent good in the paladin. In his hand, Sergei's hilt generated a Sun Blade: the Heralds had finally found the the sword of sunlight.
Resting with the barbarians for the night, the Heralds of Dawn contemplated their accomplishments and increase in skill. Ajuni learned to tap into the land, creating hallowed places; Izek became straight-up more feral, his barbarian instincts honed by the mountainside; Ghalwin's new relationship allowed him to channel radiance into any strike; and Tobias invented a self-affirmation mirror that could enhance the abilities of those who believed in themselves. The gnome also crafted further prosthetics for Ajuni, ensuring his sister had artificial fingers and toes to make up for what Delban had took from her.
Feeling better in the morning, they went to Ten-Zras' vault, where they found seven ghasts protecting Mormeros' rotting body. Strahd had intentionally let the warlock get as far as possible before snuffing him out, but left the servants who had carried him there. With disgust, the party slaughtered the undead and recollected the body of their old ally into Ghalwin's bag. To ensure they never came back, Ajuni reduced the ghasts to ash in a fireball, and they planned to leave the temple for good.
On their way out, however, Kasimir informed Ghalwin he would not be joining them; the mage was intent on getting into the temple, one way or the other. Ghalwin pleaded that Kas gain favor in the same way as Ajuni, fearing that he could never outpower or outwit Neferon. The two reaffirmed their trust in each other, and though very hesitant, the dusk elf walked with the Heralds to the temple floor. He pleaded his case to the inscrutable face of the God of Secrets, allowed himself to be judged, and was disintegrated.