Official casting
Robert downey Jr as Iron Man
Scarlett Johanson as Black Widow
Jeremy Runer as Hawkeye
Mark Buffalo as Hulk/Bruce Banner
Chris Hemswoth as Thor
Elizabeth Olsen as Scarlet Witch
Chris Evans as Capitan America
Aaron Johnson as Quicksilver ( it's rumored to be appeared )
Chris Pratt as Peter Quill
Zoe Saldana as Gamora
Karen Gillan as Nebula
Dave Bautista as Drax
Vin Diesal as Groot
Bradley Cooper as Rocket
Brie Larson as Capitan Marvel/Carol Danvers
and
Tom Holland as Peter Parker
also i'd keep dardevil , jessica jones , luke cage , elektra and iron fist from their netflix shows
Fancast
First the other defenders :
Felicia Hardy
Maika Monroe is one of the actresses that i wanted to cast in a CB role and i felt Felicia is the most approriate , she started her career playing in drama then she was a scream queen in It follows then she was a badass and dangerous in The 5th wave , she is also a great actress who is versatile and has action/sci fi experience , she was also a badass in the 5th wave and also an anti hero in the beginning and she has done physical work there and is a dancer herself making her not stranger to do her own stunts , she has also the age , the athletic body to play Felicia
She Hulk
That might be an out of box thinking yeah i know but i wanted someone younger and has experience with both TV and Movies and also tall and Tamsin fits that , she is a great actress who is also very funny and has the energy i have seen that on interviews and is not stranger of playing comedy roles and her self expressed interest of doing stunts , she is also tall at 5'10 like the character , she is also rough , has voice of she hulk , is very versatile so playing shy won't be a problem , has an athelitic body and she is also a model so she can learn how to use her own body and with training she would perfect and having played characters who are with law would a nice jumping point of playing her i know most people will complain because they have only see her on Kamelot and fits more regal roles but if you see her on Chalet girl , Keeping Mum , St Tritain and the lovers you will see how she is perfect
Second : the inhumans
Crystal
I wanted an actress who has experience with both Tv and Movies because Crystal might appear on Agents of the shield , Haley Ramm is a young underrated actress who is known by her work on chasing life and the originals , Haley had done a variety of work , Haley had proven that she could be soft spoken and demure as well as a dark and tough girl in originals , she is also close to Aaron Johson's age because they were love intersets , Haley also is a trained dancer so she can do her own stunts
Medusa
I wanted a younger actress to play Medusa and i settled on Rebecca ferguson from White queen and Mission impossible the latter had shown that she can handle physical role because she had done action in there as well some stunts also she had shown her taking on darker like themes and could pull over a stoic and charistamic queen also the reason is her role in White queen where she portayed a queen who seeks to stay on her kingdom as her role as a Queen she had experience with a leading type role and Rebecca had proven to me that she could handle Medusa Regal and stoic qualities also she had a royal look which would benefit the role of Medusa as a queen and a leader and she had shown power and dominance in White queen it would help the role of Medusa
Gorgon
Zachary quinto is a great versatile actor who had done plenty of works and the reason why he is my pick for Maximus the mad is because his role in heroes as the sadistic killer Skylar which helps out for his role alot and his role in star wars where he was a genius which also helps out of playing Maximus
Triton
Triton was a bit of hard to fancast but i ended up going with Sam Clafin from hunger games , he's a great actor who is very versatile also his work in hunger games won't go either he played an arrogant and cocky person which is a good point of playing Triton and he is not stranger to physical work
Karnak
Rupert Penry Jones is a great fit here yeah i know he needs a ton of makeup but he had the talent to pull over the character , he is a great actor having played intellegent would be a good point of playing the genius of the humans , Rupert has also done fighting moves which would be perfect for playing a martial arts expert and he needs alot of makeup to look over the character
Next xMEN
wolverine
The X men might team up with the avengers we have seen Both Scarlet Witch and Quicksilver in there so why not bring The others to the table , Kit Harginton is the fan favourite right now for Wolverine and i do agree he is small standing at 5'8 , he is rough and has the voice needed for the character , he is the best choice he has the emontional range and can certainly leave a mark on the character , he is a great actor and could certainly play the character for a long term
Jean Grey/Pheonix
i've seen Holland Roden fancasted on every redhead character and Jean was one of them so when teen wolf will end the doors are open for her to play mature characters , she is a terrific actress , possesses the age range and the body , her character in Teen wolf is a strong character who had some weaknesses and this is way similar to Jean Grey Holland had proven that she is a terrific actress proving that she can handle both sweet and darker themes of Jean Grey when she was Possesed by Pheonix , she had the presence and the ability needed to play the character plus she's a redhead like the character
Cyclops/Scott Summers
I know Cyclops is supposed to be 6'2 and Richard is 5'10 but my pick for Wolverine is small so i cared less Richard Madden from Games of thrones great at action roles ( GOT and Klondik ) he had shown that he could pull over Cyclops and bring something new to it in a new roboot of X men he had shown a great ability as Robb Stark and can play a smart but a bit naive person . Richard is British but had done a great Americain accent in the miniseries Klondik he can certainly do well with my pick for jean
Storm/Ororo Munroe
Gugu mbatha Raw from Doctor who , Touch and belle based on her performance there she'd do really well taking on darker themes and loose themes along with strengh ones , she had also played a queen which is a good point of playing Strom the leader of X men i really think she's the best who could pull over her also it gives her some sci fi creds she's a good actress so her being on X men universe won't be a problem she also fits the age range give her training , blue eyes and africain accent and she would be more than great
Rogue/Anna Marie
I wanted a younger actor to portray Iceman and i choose Jake T Austin from The Fosters , he is a good actor who has already an experience with Comic Books voicing blue beetle and also he had done comedy before and could totally pass off as a comic relief , he can play sarcastic and he is also at the same height of the character
Kitty Pryde/Shadowcat
I have seen Odeya in a variety of roles and i have her in the MCU as Kitty Pryde , Odeya is fairly known by playing weird and Dark characters but in fact she is very versatile having done lighthearted work in the Goosebumps and See you in valhala , she appears in interviews very delightful and she can also handle the innocence and darker themes of the character , she is also jewish like the character
Next Cloak and Dagger
Skyler Samuals is a good rising actress who is mainly known of playing women in tough situations like she did in scream queens and the nine lives of chloe king , she is not stranger to playing dramas and also playing mature women with issues , she is also young enough to play the character for a long term because Dagger was 16 when she had her powers and she is slightly older than Peter Parker , she has the dramatic chops and emontional range making her the perfect pick , she is also not stranger to some physical work with more training she would be perfect
Stephan James is a great also young rising actor , in Selma he had a terrific performance making him the best choice for Cloak and i do think he can bring him to life showing in his movies that he faces Racism and disability ; he has also a great screen presence and could do the chemistry with my dagger pick
Part 2 will have the fantastic four , the runaways and some villians that i think might appear