Who do you want for omega scapes 3 and 4?

[Reynhart]

and in case you're not aware, Bahamut, Alexander, Crystal Tower, World of Darkness, Diabolos are not original to FFXIV. it didn't start with Omega and Rabanastre.

Just a tiny bit difference here...all of those are incorporated in XIV's lore. They have a real reason for being there. Omega is litterally "Look, we picked the characters from past FF and didn't make any effort to make them part of XIV".

Someone on this topic mentionned how we could have Hojo being a Garlean scientist. He could have been the one to create the Resonant, and maybe one of those resonant could be called Sephiroth and become mad from the echo's vision. That's how you can make fanservice. But just putting Sephiroth in Omega with no background whatsovever is lazy.
Another thing they could have done better is replace Regula by Kefka, and make him become hungry with power after facing the Warring Triad. It could have given us a special Tower of the Gods 24-man raid where each group would have faced one member of the triad.

That's why you had a long queue of people wanting to see Kefka. Going in depth, the fights are engaging and fun to do. Mechanically speaking. But throwing fanserive just like that won't do, you want SE to respect the player's memories so they will make it look good on every sense.

Frankly, I felt that the Kefka fight was boring. No real phases, no transition, just hitting him from 100% to 0. It really felt like the dev team was saying "Well, if you want an engaging encouter, go beat savage, we don't have time to make this version engaging". But maybe it's just because it's obvious now that Savage will have a whole new phase, something we didn't know the first time we faced ExDeath.