Hi everyone, I've started a Slumbering Tsar game and we're two sessions in. For this campaign, I restricted character creation to core-only with a system of unlocking new things (abilities, spells, classes) as they probe deeper into Tsar. One player, however, has challenged this decision, stating that it is a power play to keep the playing field uneven between the player characters and the opposition due to the fact that there are creatures converted from Tome of Horrors and Creature Collection III.
The player had a character die in the first session, and repeatedly called attention to anything that was not core afterward, and in the session that followed. What I don't want is this to fester and grow into something more severe, compounded by each character death. I have talked to him a few times since, but I wonder if anyone else has dealt with this before. Any advice for moving forward?