Butterfly Island oddities (A BFDI and Mlp g3 crossover au)

One day Golfball and Basketball were experimenting in Golfballs underground factory, testing out new inventions. Expect something went wrong - while they were testing out a what they tought was a ray gun, the device opened a portal to a beautiful peaceful island - a beautiful tropical island. Before they enter they called Tennisball. The more objects to enter the better. They tried looking around for anybody, but only found ponies.. talking ponies.. some were pegasuses, some were unicorns, others were earth ponies. Golfball and Basketball asked around about the place - they were on the Butterfly Island. As time passes by, the ponies start reporting anomalies and missing ponies... And Golfball and Basketball are the ones that need to help. The wisest and smartest pony there, Kimono, worked with them, trying to figure out what was happening.

What is that anomaly? Where were the missing ponies?
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