The item: Odd Incense increases all Psychic pokemon's attack by 20% while Mind Plate makes Arceus a Psychic Type.
Why, even Twisted Spoon also does the same as Odd Incemse.
The Odd Incense can be found in the Cerulean Cave along with Mewtwo himself.
You can't.
Cerulean Cave. 2F
at the cerulean cave
in cerulean cave
You give an odd incense to Mr. Mime (found at route 218) and put 2 of the OPPOSITE gender in the daycare. Wait for the egg. It should be Mime Jr.. I hope this helped! ;-)
eat pie!
It can be found in Kanto in the Cerulean Cave. ChaCha!
Breed Mr.mime while holding an odd incense
In Diamond it is in the ruins with the Unknown, I am not sure about Platinum though.
lead
U know the cave but not the spot? Have fun spelunking!