Honestly  James heller is basically a one man army  post prototype 2. I had a few ideas that might be a interesting crossover :

What if solid snake was sent into racoon city during the outbreak possibly under classified orders from the president of the United States?

What if   rifleman Jack Cooper and  BT-7274   found themselves in the middle of the Rubicon conflict from armored core 6 likely through a ftl jump error?

What if Dracula from Castlevania found themselves in yarhnam to seek a potential way to bring back his wife?

Fun Fact: It is in the "canon" that Alex Mercer was able to withstood the power of a nuke and he only needed a single crow to put himself back together so that he needed a bit of biomass to regenerate into a whole. but The virus best feature is adaptability. the prototypes of the Blacklight Virus are pretty much DC Doomsday but with self-awareness in the mix. because James Heller in Prototype 2 at the end after he consume Mercer. He is capable of unleashing tendrils large enough to engulf all of Manhattan now think about what Alex can do.

The Arasaka corporation entering MHA or Dark Schneider entering Hazbin Hotel

Quirks are fundamentally dna in the mha world, so heller should be able use the quirk of any person he absorbs in this world.

Special ideas just for you that might interest you.

1. What if the Kamaboko Squad (Tanjiro, Nezuko Kamado, Zenitsu, Inosuke, Genya, Kanao  and Shinobu Kocho) from Demon Slayer got sent to Resident Evil Village instead of the Infinity Castle and helped Ethan Winters save his daughter Rose from the 4 lords and Mother Miranda.

2. What would happen if Mother Miranda from Resident Evil Village arrived in Demon Slayer during the Swordsmith Village Arc and found the Blue Spider Lily.

3. What if Alastor the Radio Demon from Hazbin Hotel arrived in the scp foundation and became the most dangerous Keter Class scp.

4. What would happen if Emperor Amadeus, Sir Shootsalot, Professor Archimedes, and the Executioners from Don't Join Team Red invaded Hazbin Hotel.

Feel free to choose which of the four you find interesting.

What if:

- Ben 10,000 entered MHA?

- Ghost Rider arrived in The Boys universe?

this was the best story so far

Alice (Resident Evil) in My Hero Academia

You should do what if Immortal Kakuzu landed in mha

The remaining 3 requests!

1. What if the four knights of Gwyn arrived in Fire Emblem Echoes?

2. What if E-102 Gamma and Emerl (Sonic series) arrived in Blue Archive during the millennium school arc?

3. What if the Undercity (Forsaken capital and after the events of the shadowslands meaning it's ruled by a council instead of sylvanas) arrived in the world of Fairy Tail, how would the inhabitants of the world react to undead creatures who are still dealing with the aftermath of sylvanas's betrayal and trying to be better?

the biggest issue i have here: episode one and chapter one of the manga for MHA states that a hero can still be licensed even if quirkless, and EVERY story on this channel acts as if the government can't just spin a story that it can not be identified and or claim the target has a metamprph quirk (see shigaraki 's armored form), also All Might still had to renew his license to fight in the war arc legally (despite being quirkless at the time)

Do you know funny enough there is a fan-made skin of the prototype series for Doom Slayer along with a attack on Titan / parasite skin for Doom Slayer so imagine the prototype skin merge with the Titan parasite skin it might be too overpowered so I say if possible just give to Marine those skins and find out what kind of mayhem would happen

What if Doctor Doom was in Overlord

James Heller in Hazbin Hotel

what if tony stark, bruce wyane, robert roberson, Lex Luthor, Ivo Robotnik, Eggman, and david xanatos (disney gargoyles) were in MHA

Can you cross the invincible into my hero academia it will be greatly appreciate if you do this crossover

What if Brave Cereza the Legendary Umbra Witch of Fashionista from Bayonetta 3 entered the Stargate Universe as she was walking around and was doing the Fashion Runaway at the streets and was accidentally entered into the portal of the Stargate. as they interrogate her of what she is. some scientists think that she is beyond human comprehension.

In the fight aginst afo and shigiraki he could have tried to absorbe them, but maybe that would make the storie too easy.

What if jack cooper and BT-7274 entered mha or danmachi

What if Alex Mercer the True Blacklight Virus entered the Resident Evil Universe.