The fightmon expirement is a part of fightmon history. The fightmon expirement happened in 1050 CT. Scientists were trying to find out and study how fightmon evolved, and to get fightmon to evolve at the right moment they would force them surgically by putting some kind of formula into the E-chamber of a fightmon, therefore causing it to evolve. But when one of the scientists was performing surgery on the fightmon, rather than putting the evolvation formula, he put some kind of vitamin acid on the fightmon. That certain vitamin acid causes fightmon to become very aggressive and seems to make them grow and sense it was put in the E-chamber of the fightmon, It also mutated them into monsters with blades, spikes, and fangs. And this isn't the worst thing yet, all the mutated fightmon had to do to spread this was get close to another fightmon. Luckily, the vitamin acid has no effect on humans. This ended up with a lot of mutated fightmon, no theory on how fightmon evolve, and scientists barely escaping alive.