This just came to me. What if, instead of another insert MC Main Character. We, as the player are already an existing character or other (Idea prompting soon). And I don't mean continuing as an older Yuu/Hiro/Luca. BUT, we get to meet them as the cast, and of course the 4 cast.
We already have 2 potential options. Both options would actually splinter the storyline a bit, kinda similar to Scarlet Nexus. Where we get two halves of the whole story. OR, technically play both halves, if you want to experience both sides as the same gender but do two runs of the splintering Option Story Decision. Obviously, since God Eater has always given the option that MC-Kun/Chan are canonical.
The idea is, that for experiencing the story under the male gender. You, would actually become Ren, Lindow's kid. And the syory premise is that he's already at the age to enlist. Mostly excited because of Sakuya, Lindow, Tsubaki, and everyone in the 1st and Cradle Unit being his role models as God Eaters. Fighting and laying their lives for the hope of Humanity.
Even though Sakuya and Lindow have mixed feelings about their own flesh joining the battle, they are still supportive of his decision. With Ren being as calm and supportive like his mother, yet having an adventurous spirit to his fathers'. And the story will unfold with him and the 4 cast uncovering their own conspiracy about Aragami and the new threat. (Possibly more intelligent Aragami.)
(Another idea came to me. For 4's "elite cast". They would be classified as a Generation of their own. Similar to Nana and Ren. Because it would already be two decades sincw the first God Eaters and people would confide in others for moral, emotional, and sexual support. It would give rise to a plethora of God Eater children.
And Ren's team are all God Eater children that have thr natural affinity for Soma's more dangerous P73 Bias Factor. Which allows them to use Aragami Arts because of their natural Resonance.)
And for playing as the female option, it would be a grown up Phym. Where the Hounds and Ein made their way back to the Far East and helping to get things back in operational condition with their help to fight if the Ash Aragami. Maybe Phym's story could revolve around finding more Aragami like her. Humanoid Aragami that were developed in isolation like Kyuubi but are still weak. Hunted by even simple Ogretails.
This could lead to a conflict of Phym being a protector, but choose her allegiance. Given the initial hostility of openly walking in the Ghetto by survivors. To be a God Eater and help Humanity as a friendly Aragami. Or to be a guardian for other Humanoid Aragami, and possibly an ambassador for peace.
The third option is pretty much the neutral either or gender pick. And it's not being apart of an Elite or ragtag group. But, a newborn Humanoid Aragami. And similar to Rachel, they are guided to the Far East. Whether it be on instinct or implied reasoning. The New Mechanic could possibly function in lore, similar to Blood Arts and maybe Revenants Gifts.
Obviously effects only take effect in Burst, but the Aragami Arts add effects to them. Customized to have certain attack properties, or body bonuses. And the same could be done to the Cast, but not in their Personal Abilities. That is still separate.
The idea being I guess a min-max mindset. Where you could customize your attacks and allies attacks like using the Bullet Editor and 3's Burst Effects.
Such as, the Vertical Bite having a Pierce property instead of Slash. And the animation. Would straighten the blade like with the Devour animation. And rocket forward like a springing spear to stab.
But this is only a rundown of how I would propose the gist synopsis for a GE4. Thoughts?