From Rebirpedia, the Pokémon Rebirth
The Dark Ball is a
variant of Pokéball devised by
ex-Team Rocket Super Elite operative
incorporating research from
A Dark Ball works by implanting a psychic transmission receiver, similar to how most Pokéballs implant Trainer IDs, which
is then used to harness the victim Pokémon in
and negative emotions transmitted from the Dark Ball's user via the control helmet
they wears. This allows said user to control the Pokémon's actions.
Dark Ball 0.1 overrode the controlled Pokémon's moves with Shadow
Moves, which negated all type differences. It also temporarily forces a
to 100. However, it suffered from the same flaw that plagued the Shadow Pokémon
project. A controlled Pokémon could override its 'programming' if an outside
source was able to remind it of positive memories.
Dark Ball 0.2 resolved the override issues from its previous version, implementing an audio block protocol which ensures the only voice the controlled Pokémon would hear
is the one belonging to the figure wearing the control helmet.
Further modifications allow
the user to unlock abilities in the controlled Pokémon
that were previously unattainable.