It's hard to play favorites with a cast as good as FFIX's. I still think it was a shame that Freya has about as much of a role in the narrative from Disc 2 onwards as Amarant though. Trance in IX is just kind of a weird idea in general. As in, there's no real in universe reason for why any of Zidane's allies can use it. It's like having everyone of Terra's non esper-blooded friends in FFVI be able to use the same transformation as her. That and it makes some characters worse like Quina, who gets locked out of her best abilities for a while.