Ok hear me out on this. Idk if this has been talked about before but I wanted to talk about it now.
My bf and I were rewatching AOT and we got to the crystal cave where Historia is almost convinced to become a titan and eat Eren. When we got here a thought popped in my head:
> "The attack titan is somewhat different than all the other titans because it possesses the will to *never obey others.* Eren has the founding AND attack titan, so if Historia ate Eren in the cave and she took on both the founding and attack titan, would she still be bound to the king's peace rule?"
I have watched AOT before and this is the first time I truly questioned the power of the attack and founding titans bound together by royal blood.
We talked about it and came to the consensus that, yeah, the king's peace ideology would have been broken, not because the attack Titan is stronger than the founder, but because the attack titan is a symbol of freedom and would not be bound by the king's rule. If Historia got both of the titans, she would have had the power of the founder unbound by the king's peace ideology!
They obviously didn't know the significance of the attack titan at the time. So it's understandable that Historia didn't eat Eren because she thought she would just be under the same ruling as all the other founder's predecessors. But imagine if she did! Imagine how different the story would have turned out if Historia was able to use the founding titan to its full potential!! Would the rumbling have happened? If so, would Historia choose to do the rumbling sooner or later than Eren? Would se reenstate the peace ideology? So many questions.
I haven't read the manga so I'm basing this on the show. If there is a bit of lore somewhere in the manga or in the anime that I missed please let me know because I'm dying to see if my theory holds water!