Additionally, Ditto can transform into organics and non-organic things by reconstituting its whole cellular structure which in reality a group of Ditto family can be completely unstoppable, and if they can utilize their power efficiently, they can overturn the Planet.
If you are not a Lugia enthusiast please never undermine its power if you have never heard about its butterfly effect. If it happens to flap its wing believe that it can cause a hurricane somewhere in the world take your time and think through this, every time its flaps its long wings will cause a shocking storm that lasts for 40 days.
If this doesn’t surprise you then keep in mind that the only way it moves is through flying and when it flies it will flap its wings for so many time before getting to its destination, so it will cost storms after storms just by flying around. For this reason of being able to affect the climate and the whole world, it deserves a place on this list.
Giratina is dangerous to other Pokemon as it has a potential to cause havoc so much that the legend that created him says that after he went ahead and banished him from the distortion world hoping that he will remain there forever. So, if Arceus that created the universe fears him, who are we to doubt?