This is based on an idea I had: What if Sodor Fallout and MLP Infection AU were mixed together?

What was supposed to a payback prank on Rainbow goes down the drain when some ponies coughing, crying or vomiting blood... Not only that, but some ponies get unexpected, and sometimes horrifying, transformations like changing into changelings, vampire, blanked ponies, etc! Plus, some creatures are attacking each other either because they can't help, they're being forced against their will or because it's everycreature for themselves. Things only get worse when the nuclear power-plant on the Brendam branchline blows up leading some of engines and ponies getting mutated... It's Thomas, Edward, Rainbow, Scootaloo, Windy Whistles and many others to try and find survivors and find out how did all this happen and who is the mastermind behind it all... Secrets are revealed (Even some that have been around long before the disaster), friendships get strained and put to the test and not everyone lucky to tell their story...

Headcanon:

Scootaloo is adopted by Bow Hothoof and Windy Whistles after her original family pass away.

Pear Butter and Bright Mac are alive.

Applejack and Pinkie are NOT cousins and Big Mac is married to Marble.

Queen Chrysalis is reformed here and married to Twilight.

The events of Season 8-9 (With the exception of The Washouts, Sound of Silence and Best Gift Ever) of MLP and the events of Season 22-24 (With the expection of School of Duck, Rosie is Red and the episodes written by Michael White) of Thomas are not canon.

Sweetie Belle becomes a metamorphosed changeling when the Changeling Hive is need of volunteers to help protect the changelings from danger.

The fanfics Past Sins and Winter Bells are canon. Links: https://www.fimfiction.net/story/41596/past-sins and https://www.fimfiction.net/story/71883/winter-bells

Seeds of Darkness are canon to my series. Link: https://www.deviantart.com/estories/gallery/46507186/vector-comic-seeds-of-darkness

Following after the poor treatment the Wonderbolts gave her in Newbie Dash, Rainbow quits the Wonderbolts and joins the Shadowbolts instead. Don’t worry, she doesn’t become a villain. For my headcanon, the Shadowbolts are real and instead of being performers or soldiers like the Wonderbolts, they are vigilante superheroes. This was based on an idea by King Grover: https://youtu.be/u003OBHXl7A?si=3HUkwzeYGOZY4X9o

Note: After the final battle, Lady uses her magic to bring everyone back to life and have everything back to normal at the end, though sadly the only ones who aren't brought back to life are The Wonderbolts, Sugar Belle Cozy Glow, the Student Six (Expect Ocellus), Nia and Rebecca.

Link to Sodor Fallout by TidmouthThunderbolt: https://www.wattpad.com/story/225257547-sodor-fallout-a-thomas-the-tank-engine-au

Thomas, Edward, Oliver and the Fat Controller Vectors:
https://www.deviantart.com/aidenkwonproductions/art/Edward-Tired-Transparent-1071225957
https://www.deviantart.com/ntttefan123456/art/Thomas-Season-7-PNG-Front-1091771047
https://www.deviantart.com/tfe52thomas52/art/Oliver-the-Great-Western-engine-937879918
https://www.deviantart.com/smellyknickknacks/art/Transparent-S3-Sir-Topham-Hatt-920557489