Hmm.. it looks like there could be variations. In my game, Icara survived the battle with Leandra, I did the soul forge ritual but then in the immediate aftermath of the battle, still in the first garden, Astarte banished the Leandra half of the soul-forged sisters and what was left was Icara both here at later at the Academy.
I suppose yours played if Icara doesn't survive.
Btw, I had an interesting glitch. After battling the death knights Zandalor and Icara/Leandra didn't follow me down from where they were hanging back up the hill. I went back up, Zandalor then followed but Icara/Leandra never did. I fought the void dragon without their help.
