Mewtwo
Correct
This Pokémon isnt the one with the least weaknesses, but the typing makes it a formidable defensive Pokémon (along with its stats)
Dialga
No
Ferrothorn
No
It’s typing is Unique.
Heatran
No
It is partially a poison type
No
Toxapex
No
It has two formed at this point in time. One is pure poison
Weezing?
Correct, my Pokemon was Galarian weezing
Opposite to my counterpart I don’t have a Mega.
Thats not a formidable defensive Pokémon but ok
Milotic?