Fan Theories

I think the planet we saw in the 2015 FF was Mandala as it had nerve impulse and energy surfing it and also kept victor alive

What will Doctor Doom's motivation be? (Update)
Little update to my theory about MCU Doctor Doom's motivation, so we all know Doctor Doom is gonna replace Kang as the villain of the multiverse saga, however he has yet to debut in MCU and we know he will be played by RDJ, but will his motivation be in MCU? My theory is how he will have dreams of his variants dying across the multiverse, he will see his defeats in 2005 and 2007 Fantastic Four movies and even in that 2015 one, and he will keep dreaming how his other variants die everytime at hands of super powered beings, whether it's Avengers, X Men or Fantastic Four or someone else, and so Doom will discover the multiverse and find out how dreams are mirrors to alternate universes and so because of it he will make a vow to exterminate anyone who has superpowers whether it's mutants, inhumans, eternals and he will take his mission to such an extreme he will target even cosmic beings
Here are some cosmic beings in comics

Out of these beings we can see Skyfathers who appeared in Love and Thunder

Watchers who debuted in GOTG 2

And then Uatu himself in What If

Celestials who also debuted in GOTG

And had their lore expanded in Eternals

Eternity who debuted in Love and Thunder

Eon who's statue appeared in Love and Thunder

Mephisto who was mentioned in Agatha show

And Mistress Death who also appeared in Agatha show

Not to mention Galactus debuting next year and RDJ Doom might be from his universe

So like imagine Galactus destroys Earth and this further motivates Doom
There is also Phoenix in X Men films

Basically he will say how he should be only person in the multiverse to have superpowers, he and his variants of course, and we saw on Comic Con how RDJ was surronded by other people dressed as Doctor Doom so my theory is RDJ Doom will assemble his mini council of Dooms all played by some of the most popular Doom castings like Cillian Murphy, Nikolaj Coster Waldau, Mads Mikkelsen or someone else, and this Doom won't really be God Emperor Doom but rather Doom Above All or amalgamation of both, but hey it's just a theory, a film theory

Why Stan Lee as Old Steve Rogers would have made much more sense?
We saw in Hulk(2008), how the old man(stan lee) was dead by drinking hulk's blood but was then seen in the next movies, so he made it? 'Cause he was Steve Rogers, How did an old man(Stan Lee) made into the Avengers party in 2015, and even drank something meant for fierce warriors and also how does he get involved in EVERY major sequence