Question

According to the EV list, he gives off one HP ev, but I wanna be sure this doesn't change should he use transform.

Comments

this is a very good question

Answer 1

Nope, Ditto keeps his own EV's when he transforms.

Ditto gives off one HP EV, but when he transforms, he still keeps his own yield, meaning he still gives off the same one HP EV when he is transformed into another pokemon. -DarkTyplosion

Source

Comments

what about IV's