I haven’t played much with the new system yet, but from what I’ve read the big changes are wants come in long-term, short-term and immediate, and there’s a fears system, so could something be done with that? Instead of seven emotional whims, immortals have to complete 4 long-term wants and overcome three fears? Or something along those lines.
Or something else I thought could be fun, could each immortal have to complete a unique achievement? Even if you discount the ones that use multiple sims, there’s still plenty that a single sim can complete.