I think that The French Snk community is still one of the worst in terms of theories LMAO..
Their ending scenarios tells a lot.. :
1_Eren will kill everyone and his friends and go back to his baby and Historia (for them he's 100%)
2_Eren will be killed by Mikasa

For a lot of them he's 100% the father of Historia baby (because a known YouTuber said it once lmao) and Mikasa for them is just here to kill Eren and stop the rumbling They're Pathetic seriously Mikasa for them is just a killing machine and there's zero feelings from Eren to her

Yeah EReH iS da FaThEr lol i'M sUrE bEcAuSe hE tAlKeD tO hEr iN tHe ChApTeR

For me both are so cringe whenever it comes to the "baby daddy theory" or to "mIkAsA wiLl Kill EReH" if you consider any type of this endings then you have to read the manga again