Look at Blue Sonia's ultimate (which is still high on most tier lists as a leader). Despite being very similar to Red Sonia, she's considered a better roll due to her leader skill being much better for rows and having more awakenings. In addition, she fits perfectly on blue teams like Neptune Dragon and Idunn and Idunna + Ryune. If they were to tweak Ultimate Red Sonia's leader skill and awakenings to match Blue's, that would already be a step in the right direction. Unfortunately Gungho screwed Red Sonia (and Freyr) over with Gadius, so she can't get the sub benefits Blue Sonia gets right now until more red/dark monsters are introduced.
There's another potential issue of player expectations.
Will Ronia eventually get another evolve? Sure looks like it. Reincarnations are a perfect magic hand wave to give GungHo a mulligan and rewrite all the older cards to meet more modern meta standards. The core issue is of player expectations regarding her sisters. As soon as she gets a 8* reincarnation, there will be immediate demands for a 9* reincarnation of Gonia and Bonia. 9* is evolved MP dragon territory, which has the severe potential to piss some people off royally if the GFEs start becoming serious competitors to them.
For example, how pissed would Shiva Dragon users be if 8* Reincarnated Ronia had a leader skill of "2.5x to Dragons and Devils, 2x ATK on a turn a skill is used." Yes, Shivagon can always achieve 25x every turn unconditionally as an advantage, but many would cry fowl if Ronia came even close to matching Shivagon in power (and could be situationally more useful, such as against high damage absorbs]. And then her 9* sisters? They would need to be even stronger than that.
Which then begs the question, just how quickly with the MP dragons become obsolete? Should MP dragons get Uevos to compensate?
Regardless, Reincarnated GFEs will surely not be in play until the next tier of evo materials above jewels is released. Not looking forward to seeing what types of dungeons actually drop those materials.
