So, I have defeated the golems and found the crystal evidence for Berra, had the conversation with Anaximander, been to Girkra, gone through the transporter and listened to the shade, fought Vahnatai, followed them eastwards and listened to Rentar Ihrno on the pedestals. Yet Erika won't discuss the Vahnatai with me and Ostoth only lets me ask about a weapon for giants or dragons.
When opening the tunnels beneath the Giants and Troglos in previous versions there were crystals to collect there too in older versions. I've been back more than once and nothing.
I only have the alien beasts and the Citadel etc to do leading on to Vahnatai. I like to get Demonslayer from Rentar's rooms before Linda goes rogue again before leaving Rentar for the very end. Do I have to fight Rentar to get evidence to get a weapon to fight Rentar with? I have the warpmetal blade, I have the Radiant Soulblade from Carmine. Do we get an anti crystal soul blade (the one in the golem factory was very tough) or not?