>>57899954
Now, if we imagine that Fug gets weaker over time - for whatever reason, then those events make more sense. You have an overall downward trend, which leads to Rayquaza being weaker than Primal Kyogre and Primal Groudon. To counter this, Fug got a Mega evolution 1000 years ago, and in present time, during Delta Episode, Fug got its chemo power up to keep the Mega evolution going.