You won't miss anything. But I highly recommend talking to her and to actually fail the first time in the battle. Just make sure you save right before it. Why? Because the cut scene you are about to see is simply amazing and gives you a good idea about the stakes and what the shadow curse is able to do. The battle itself is not as hard as people make it to be. It is easy enough on tactician and winning gives you more lore and some nice loot.
Just my opinion what should happen, if you skip Isobel: As you are not the trigger (these events don't unfold because of you, they unfold because of Isobel) they should happen with or without you, once a timer runs out. So if you never talk to her, you will lose the Last Light Inn. Main problem I see is making the player aware of a running timer. But in that case your choice would have an actual consequence.
Last edited by Jones76; 25/09/23 08:19 AM.