Use Mewtwo, Mew, Lugia, Ho-Oh and Celebi as rentals in Prime Cup (includes multiplayer).
Normally, Mew and Celebi can be unlocked.
Mewtwo, Lugia, and Ho-oh must be traded from a cartridge.
The number of slots is hardcoded, so Caterpie, Metapod, Weedle, Kakuna, and Magikarp have been removed and Mewtwo, Mew, Lugia, Ho-Oh and Celebi are added.
The movesets for Mew & Celebi were copied from the normally unlockable Mew & Celebi, while Mewtwo, Lugia & Ho-Oh's movesets were copied from 'Vs. Rival Round 2', where you fight those 3 Pokemon.
Use "beat" to patch.
Tested using Project64 & Everdrive 2.5. Note there may be the same issues on Everdrive 2.5 as would be present in an unmodified ROM.
Pokemon Stadium 2 (U) [!].z64
MD5: 1561C75D11CEDF356A8DDB1A4A5F9D5D
SHA-1: D8343E69A7DC63B869CF6361D87CDE64444281D3
CRC32: A9998E09