You can take a standard vanilla ROM and apply an NTEVO patch or use the Universal Pokemon Randomizer to manually toggle the "Change Impossible Evolutions" setting.
Enables solo play for the original 151, allowing Kadabra and Haunter to reach their final forms through leveling. Pokemon Ntevo Roms
These are some of the most popular NTEVO versions, often packaged with "Pixel Perfect" or "Widescreen" patches for a modern visual feel. You can take a standard vanilla ROM and
Additionally, some high-quality enhancement hacks like Heart and Soul build upon the NTEVO concept by adding other quality-of-life features, such as the Physical/Special split, following Pokémon, and infinite TMs, while still offering the solo-evolution fix. How to Get and Play NTEVO Games such as the Physical/Special split
remains identical to the original Nintendo release, making them ideal for solo players on mobile emulators like Lemuroid or Delta. Popular NTEVO ROMs by Generation
are replaced by level-based evolution (often around level 37).